Alex Smith threw two long touchdown passes and rookie Kareem Hunt, after fumbling on his first NFL carry, scored three times to help Kansas City down New England 42-27 in the NFL season opener.
A very loud sold-out crowd of 65,878 at Gillette Stadium celebrated the unveiling of New England's 5th Super Bowl championship banner before the game.
It was the first time the Patriots lost at Gillette Stadium when leading at halftime, a span of 82 games. They were no match for the Chiefs in the last two quarters.
Tyreek Hill scored on a 75-yarder and Hunt put the Chiefs in front with a 78-yarder to punctuate Kansas City's charge after trailing 17-14 at halftime. Hunt also had a 58-yard scamper and finished with 141 yards rushing and 98 receiving.
Hill had 133 yards through the air, and Smith went 28 for 35 for 368 yards and four touchdowns.
40-year-old Patriots quarterback Tom Brady struggled in the second half and didn't throw for a touchdown, finishing 16 for 36 for 267 yards.