MIAMI (AFP) — The Kansas City Chiefs clinched the top seed in the American Football Conference (AFC) with Patrick Mahomes throwing three touchdowns in a dominant 29-10 Christmas Day win at the Pittsburgh Steelers on Wednesday.

The defending Super Bowl champions will now have a first-round bye and home-field advantage throughout the playoffs but a third straight loss for the Steelers means they no longer control their own destiny in the race for the AFC North divisional title.

The Chiefs (15-1) look to be hitting their prime form at just the right time but the Steelers (10-6), who have also clinched a post-season berth, have now lost three in a row and sit behind the Baltimore Ravens in the AFC North.

Mahomes, who threw for 320 yards on 29 of 38 passing, was in charge from the outset, finding Xavier Worthy with a seven-yard touchdown pass before connecting with Justin Watson on an 11-yard pass to open up a 13-0 lead in the first quarter.

The Steelers thought they had got back in the game when Jaylen Warren ran into the end-zone but the score was ruled out by a holding penalty.

The frustration was increased on the next play when Steelers quarterback Russell Wilson was picked off by Justin Reid.

Pittsburgh did give themselves some hope in the second quarter with Wilson finishing off a 72-yard, 11-play drive, with a one-yard rush.

The teams exchanged field goals in the third before the Chiefs ran away with the game in the fourth.

A two-yard rush from Kareem Hunt made it 22-10 and then Mahomes found his trusted target Travis Kelce in the end-zone with a 12-yard pass to settle the contest.

Kelce, who caught eight passes for 84 yards to pass the 1,000 receptions mark, is only the third tight-end to achieve that milestone after Tony Gonzalez and Jason Witten.

“I thought it was a full team performance,” Mahomes said.