Bucs, Bears in 1st place? Who would have thunk it?

There is no way anyone outside Tampa or Chicago would have predicted the Bucs and Bears would both be in first place when they square off in Week 4.

Sure, it’s still plenty early in the schedule. Yet there’s no denying both teams are ahead of schedule.

Although the Buccaneers (2-1) come off a 30-27 home loss to Pittsburgh last Monday night, their offense behind backup quarterback Ryan Fitzpatrick has been dynamic.

Fitzpatrick started the three games for which starter Jameis Winston was suspended and made a strong argument for keeping the job. Fitz leads the NFL with 1,230 yards passing and is second with 11 TD passes. He’s the only player in league history to throw for 400-plus yards in three consecutive games.

Winston certainly has been impressed and promises not to make waves.

“It’s about the team’s success. I’m not a selfish player, it’s about our team,” Winston said. “We’re out here doing big things, and we’ve got to continue doing that.”

Chicago (2-1) is doing big things on defense. The trade with Oakland for Khalil Mack has made a huge impact in the Windy City, making up for a mediocre offense.

Mack is tied for the league lead with four sacks, with at least one in each game, and leads the NFL with three forced fumbles.

“What he has done is completely elevated everybody else on defense,” coach Matt Nagy said. “When that happens, that’s rare, to have one guy affect a team like that.”

Week 4 began with Jared Goff throwing for 465 yards and five touchdowns and getting a perfect quarterback rating in a 38-31 victory over Minnesota. The Rams are 4-0 while the Vikings are 1-2-1 and haven’t won since opening day.

On byes are Carolina and Washington.

Baltimore (2-1) at Pittsburgh (1-1-1)

Classic NFL matchup, Part I.

The Steelers have won nine straight games on Sunday nights, twice over the Ravens. But Baltimore has a rekindled offense, with Joe Flacco off to a sizzling start, helped by a trio of new receivers. Newcomer Michael Crabtree leads the Ravens with 15 catches and needs six to reach 600 for his career.

Pittsburgh likely gets back top blocker David DeCastro for Ben Roethlisberger, who is 21-3 in regular-season prime-time games at home, throwing for 55 touchdowns and 16 interceptions. Roethlisberger has thrown a TD pass in 45 straight home games, the third-longest streak in NFL history.

If this comes down to kicking, Baltimore has a huge edge. The Ravens’ Justin Tucker has hit eight straight field goals from 50-plus yards and owns the best FG percentage (90.0) in NFL history. Pittsburgh’s Chris Boswell has hit just one of four field goals; the three misses match his entire 2017 total.

Kansas City (3-0) at Denver (2-1), Monday night

Classic NFL matchup, Part II.

Another prime-time showcase worth watching, this is a series of streaks. The Chiefs have taken five straight following seven straight losses. The offense is a buzz saw: Kansas City is the third NFL team to score 38 or more points in its first three games (2007 Patriots, who were 16-0; 1967 Colts, who went 11-1-2).

Patrick Mahomes has established an NFL record with 13 TDs through three games and zero interceptions to lead the league with a 137.4 passer rating. The second-year QB credits the depth of talent around him.

“Guys everywhere,” Mahomes said. “Knowing that I have those weapons, whenever someone has to get a break — we say if you’re tired, get a break, because I know I can trust the next guy coming in.”

The Chiefs can be scored on, though, and Denver had the NFL’s third-ranked rushing game with rookies Royce Freeman and Phillip Lindsay, the first undrafted player to eclipse 100 scrimmage yards in his first two NFL games.

Plus, linebacker Von Miller , tied for the league lead with four sacks, is a Chiefs nemesis: Miller has eight sacks, 11 tackles for loss against Kansas City.

Miami (3-0) at New England (1-2)

Classic NFL matchup, Part III.

Yes, the Patriots have so dominated the AFC East that we forget there are other teams in the division. This is the one team Tom Brady has fallen to the most, 10 times. Of course, he has beaten the Dolphins 21 times.

Indeed, the last time the Dolphins won at New England was 2008, when Brady was sidelined by a knee injury.

Miami already has seven interceptions; it had nine all of last season.

Meanwhile, the Patriots have struggled to find any consistency. They rank 25th on offense — other than Rob Gronkowski, Brady has little comfort with any receivers — and 28th on defense. Bill Belichick was outcoached by his former defensive coordinator Matt Patricia last Sunday night.

But the Patriots have started slowly before and then become unstoppable.

Philadelphia (2-1) at Tennessee (2-1)

Philly likes playing AFC South squads: The Eagles have won seven straight games against them, the team’s longest active winning streak against any division.

This could come down to the running game, particularly if Titans QB Marcus Mariota still is struggling with a right elbow injury that has affected his grip. The Eagles rank first in run defense after finishing first last season and also lead the NFL in time of possession (36:03).

Cleveland (1-1-1) at Oakland (0-3)

There are good vibes by Lake Erie and bad ones in the Bay Area.

The Browns got their first win in 18 games by beating the Jets, and top overall draft choice Baker Mayfield led the way to take over as starting quarterback. Their defense has been relatively stout, led by the No. pick in the 2017 draft, Myles Garrett.

Oakland’s decision to trade its best player, Mack, and then the 0-3 start has worn thin any luster on Jon Gruden’s return. The Raiders are last in the NFL with three sacks and tied for last with one takeaway. They have been outscored 37-3 in fourth quarters and are the second team in the last 20 years to start 0-3 when leading all three at halftime.

Detroit (1-2) at Dallas (1-2)

The Lions got off the schneid with that surprisingly dominant win against New England. They have the top-rated passing offense, but they also are a sieve against the run on defense.

With Dallas struggling so much throwing the ball, look for RB Ezekiel Elliott to be very busy in this one. Elliott is tied with the 49ers’ Matt Breida for the NFL rushing lead with 274 yards.

San Francisco (1-2) at Los Angeles Chargers (1-2)

Injuries probably have ruined the 49ers’ season. After giving Jimmy Garoppolo his big payday, they will be without him for the remainder of this year after he tore his ACL against KC. C.J. Beathard, who was in over his head last year in going 1-5, steps in.

The Chargers have won the past four meetings and have a dangerous offense behind QB Philip Rivers and a ramped-up running game. Melvin Gordon and Austin Ekeler form the only pair of running backs on the same team with 250 or more scrimmage yards this season.

Cincinnati (2-1) at Atlanta (1-2)

Injuries are beginning to ruin the Falcons’ season, too. They lost free safety Ricardo Allen with a torn Achilles tendon and he joins starters Keanu Neal (knee), a strong safety, and linebacker Deion Jones on the sidelines. Jones underwent foot surgery and is out until at least Nov. 18.

Plus, defensive ends Takkarist McKinley and Derrick Shelby are nursing groin injuries.

This is Cincinnati’s third road game already, and Atlanta’s third successive home game. The Bengals come in without starting RB Joe Mixon (knee) but are stunningly successful in the red zone. They have points on their last 29 times inside the 20-yard line (21 TDs, 8 FGs), the longest active streak in the NFL.

Buffalo (1-2) at Green Bay (1-1-1)

On a high after their stunning win at Minnesota as 16 ½-point underdogs, the Bills get another NFC North trip. Hey, it’s always good to do those in September.

Buffalo’s rookie quarterback Josh Allen wasn’t intimidated by Minnesota’s staunch and physical defense. Green Bay’s doesn’t come close to resembling that group, and standout runner LeSean McCoy (ribs) vows he will be back.

Aaron Rodgers figures to throw a bunch this week, with Davante Adams now his top target.

New York Jets (1-2) at Jacksonville (2-1)

Coming off a loss that easily could linger, and with safety Jamal Adams saying the Jets weren’t prepared for Mayfield when he replaced Tyrod Taylor in Cleveland’s victory, New York takes on ticked-off Jacksonville.

The Jets have won four straight in this series, but those games were mostly against weak Jaguars teams. After the Jags struggled so much vs. Tennessee, they could take it out on rookie Sam Darnold with a sack-happy defense. And Darnold displayed happy feet against the Browns.

New Orleans (2-1) at New York Giants (1-2)

If Eli Manning gets protection, the Giants are competitive. That happened in last week’s win at Houston, and the Saints have been disappointing defending the pass.

The excitement level ramps up in the running game as Giants rookie Saquon Barkley and the Saints’ Alvin Kamara, last year’s Offensive Rookie of the Year, face off. Also intriguing: Saints WR Michael Thomas leads the league with 38 catches and 398 yards receiving. His catch total is an NFL best in a team’s first three games. New York’s Odell Beckham Jr. has a respectable 24 receptions, even if that pales compared to Thomas.

Seattle (1-2) at Arizona (0-3)

Two teams with messed-up offenses, although the Seahawks look like an indomitable force compared to Arizona.

The Cardinals rank dead last in all offensive categories and have scored a total of 20 points. Now, rookie Josh Rosen will start, and while Seattle’s defense no longer has legion-like boom, it can be tricky and ranks eighth against the pass.

A win will tie Pete Carroll with Mike Holmgren for the most coaching victories in Seattle history (90).

Houston (0-3) at Indianapolis (1-2)

Houston probably is the most disappointing team in the NFL, having gotten back J.J. Watt, Whitney Mercilus and Deshaun Watson for injury, yet not winning at all. Indeed, the Texans’ last victory came in November 2017.

They rarely fare well with Indy, which has a 25-7 edge in the series. The Colts’ next win will be No. 300 since moving from Baltimore to Indianapolis in 1984.

Adam Vinatieri needs one field goal to break Morten Andersen’s NFL record (565). Vinatieri also needs three field-goal attempts to pass Gary Anderson (672) for second all-time, and one game played to pass George Blanda (340) for No. 4.

Can’t kick about that.