JACKSONVILLE – It was a regular-season opener as one-sided and chaotic as it was hot.

The result for the Jaguars wasn't good.

Jaguars starting quarterback Nick Foles didn't play after a first-quarter injury, and middle linebacker Myles Jack was ejected for fighting in the first half. Those were early trouble spots in what turned into a 40-26 loss to the Kansas City Chiefs in front of 60,157 at TIAA Bank Field in the 2019 regular-season opener Sunday afternoon.

"This was a bad game, it wasn't what we wanted to put out there," defensive end Calais Campbell said. "It definitely stings a little bit. We made way too many mistakes today."

The game was played in 96-degree temperatures that felt far hotter.

Chiefs quarterback Patrick Mahomes, the 2018 NFL Most Valuable Player, completed 24 of 32 passes for 375 yards and three touchdowns – with all three touchdowns going to wide receiver Sammy Watkins. Mahomes passed for two touchdowns and 313 yards in the first half, and his 211 passing yards were the most by an NFL player in the first quarter since 2004.

"We gave up too many big plays," Head Coach Doug Marrone said. "They did a nice job. They made the plays. They were able to get behind us and by us."

The Chiefs, who never trailed after a 68-yard pass from Mahomes to Watkins on the game's first series, led 17-7 after a quarter.

Rookie Gardner Minshew II, a sixth-round selection in the 2019 NFL Draft, replaced Foles early in the second quarter and completed 22 of 25 passes for 275 yards and two touchdowns – keeping the Jaguars within range through the early minutes of the third quarter. The Jaguars trailed 23-13, at halftime.

Foles, who signed with the Jaguars as an unrestricted free agent this past March, pulled the Jaguars to within 10-7 with a perfect 35-yard pass to second-year wide receiver DJ Chark Jr. with 5:23 remaining in the quarter.

But Foles sustained a broken left collarbone when Chiefs defensive tackle Chris Jones landed heavy on him after the pass. Foles was X-rayed immediately and spent the rest of the game on the Jaguars' sideline, left arm in a sling.

"It was obviously unfortunate," Marrone said. "We'd really liked to have seen how the game would have worked itself out if Nick [hadn't been injured]."

Chark finished with four receptions for 146 yards, and his 69-yard second-quarter reception from Minshew set up a second-quarter field goal. Jaguars running back Leonard Fournette rushed for 66 yards on 14 carries.

Watkins finished with nine receptions for 98 yards three touchdowns, and Chiefs tight end Travis Kelce caught three passes for 88 yards. The Chiefs outgained the Jaguars, 491-428.

Jack, one of two Jaguars defensive captains, was ejected for an altercation early in the second quarter. Chiefs wide receiver Demarcus Robinson and running back Damian Williams also were penalized for unsportsmanlike conduct, with officials announcing that Jack was ejected automatically for throwing a punch.

Step by step: 

*The Chiefs took a 7-0 lead on the game's first series when Watkins turned a pass over the middle from Mahomes into a 68-yard, catch-and-run touchdown with 13:24 remaining in the first quarter; safety Ronnie Harrison and cornerback Jalen Ramsey both missed chances to make the tackle on the play. A 28-yard field goal by Harrison Butker on the Chiefs' next possession made it, 10-0; Mahomes had completed five of six passes for 141 yards at that point. Foles' 35-yard touchdown pass to Chark on the next series cut it to 10-7, but Mahomes' second touchdown pass to Watkins – a 49-yarder on a play on which Watkins was wide open – made it 17-7 after the first quarter.

*The Jaguars cut the lead to 17-10 early in the third quarter, with kicker Josh Lambo converting a 37-yard field goal with 11:36 remaining in the second quarter; Minshew completed four of four passes for 43 yards on the series. A 27-yard field goal by Butker on the ensuing series made it 20-10, Chiefs. Lambo's 23-yard field goal with 4:22 remaining in the second quarter cut the lead to 20-13 and Butker's third field goal of the half – a 46-yarder with :24 remaining in the second quarter – gave the Chiefs a 23-13 halftime lead.

*The Jaguars had a chance to cut into the lead early in the third quarter, but Fournette fumbled on third-and-2 from the Chiefs 26 and Kansas City cornerback Bashaud Breeland recovered. Chiefs running back Damien Williams capped the ensuing series with a one-yard run to give the Chiefs a 30-13 lead with 2:25 remaining in the third quarter. …

*Mahomes' third touchdown pass of the game to Watkins – a three-yarder – gave the Chiefs a 37-13 lead with 10:56 remaining. Minshew's first career touchdown pass – a 15-yarder to wide receiver Dede Westbrook – made it 37-19 with 7:32 remaining. A 35-yard field goal by Butker extended the lead to 40-19. Minshew's 21-yard touchdown pass to wide receiver Chris Conley on the first play after the two-minute warning cut the lead to the final margin.

Injury report:Foles sustained a left shoulder injury and did not return. … Linebacker Quincy Williams sustained a second-quarter knee injury and returned. … Safety Ronnie Harrison sustained a fourth-quarter knee injury, returned and left again.

Notable:DT Marcell Dareus (elbow) and LT Cam Robinson (knee) were ruled out shortly before kickoff; rookie Josh Allen started at end for Calais Campbell, who switched inside to start for Dareus at three-technique tackle. Will Richardson Jr. started for Robinson because backup tackle Cedric Ogbuehi (hamstring) also was out Sunday. Jaguars inactives Sunday: Dareus, Ogbuehi, Robinson, tight end Josh Oliver, wide receiver C.J. Board, running back Devine Ozigbo and linebacker Austin Calitro.

What's next:The Jaguars will play the Houston Texans at NRG Stadium Sunday at 1 p.m.