KANSAS CITY, Mo. (AP) – Alex Smith led the Chiefs to a quick touchdown and first-round pick Patrick Mahomes II had an impressive debut, before the San Francisco backups led the 49ers to a 27-17 victory over Kansas City in their preseason opener Friday night. Smith hit speedster Tyreek Hill for a 32-yard gain on the first play of the game, and Spencer Ware capped a 75-yard march with a short TD run to give the Chiefs a 7-0 lead. It was the only series for Smith, who finished 4 of 6 for 48 yards.

Mahomes checked in for the first time late in the second quarter, drawing perhaps the biggest roar of the night. The 10th overall draft pick had a long completion wiped out by a penalty on his first play, but later capitalized on a blocked punt with a short touchdown throw to fellow rookie Marcus Kemp. Mahomes was 7 of 9 for 49 yards as he duels with Tyler Bray for the No. 2 job.

San Francisco rookie C.J. Beathard hit Kendrick Bourne for a 46-yard TD pass in the fourth quarter, then found him for a tying two-point conversion. The Chiefs promptly fumbled the ball back and Beathard added a short TD pass to Tyler McCloskey with 10:41 left to give the 49ers the lead for good. Beathard, a third-round pick, outplayed both quarterbacks ahead of him on the depth chart.

Brian Hoyer did little to make new 49ers coach Kyle Shanahan feel good about giving the longtime NFL journeyman the starting job at the onset of training camp. He was 1 of 4 for three yards in two offensive series, going three-and-out on both of them.