SAN DIEGO -- For the first time in five years, there's an AFC West champion not named the Denver Broncos.

For the first time in four years, Mike McCoy isn't the Chargers' coach after he was fired.

Alex Smith threw two touchdown passes and ran for another as the Kansas City Chiefs beat the San Diego Chargers 37-27 on Sunday afternoon to win the AFC West.

The combination of the Chiefs (12-4) sweeping the season series from the Chargers (5-11), and the Oakland Raiders' loss to the Denver Broncos, gave K.C. its first divisional title since 2010. It gets a first-round bye and will host a second-round playoff game.

"For us it was such a big swing, to go from potentially playing a road game in the wild card to a bye and hosting a game, there was no in-between there," Smith said. "We took care of our end and got some help from Denver, so it was pretty sweet, we saw the score there at the end, and we had our deal sealed up. Pretty awesome, and to win the division is special as well, that's something that this group hasn't done."

The Chargers have lost 23 of the past 32 games and 13 of 14 against AFC West foes. It was too long of a skid for the Chargers' brass, which canned McCoy after he went 27-37.

Smith was 21 of 28 for 264 yards, with two touchdowns and an interception. Charcandrick West had both of the scoring receptions.

Philip Rivers completed 22 of 38 for 269 yards, two touchdowns and two interceptions.

"We gave ourselves a chance," Rivers said. "We turned it over twice, which killed us."

Antonio Gates dropped what would have been an NFL record touchdown reception for tight ends in the fourth quarter. After Gates, who earlier tied Tony Gonzalez with his 111th career scoring catch, was unable to collect Rivers' pass, Josh Lambo kicked a 29-yard field goal.

Gates was being tracked by numerous Chiefs defenders.

"It was drawn up perfectly," Gates said. "I knew the second touchdown was going to have be a spectacular catch. Unfortunately, I wasn't able to make a catch."

Tyreek Hill returned a punt a franchise-record 95 yards for a score in the third quarter's final minute, extending the Chiefs' lead to 34-17.

"All in all, it was a good win, all the way around," Chiefs coach Andy Reid said.

After climbing back into the game, the Chargers proved again to have no answer for the Chiefs' offense.

On the same play, which resulted in his first touchdown catch, West was all alone near the goal line as Smith rolled to his right. Smith's quick toss covered 4 yards and the Chiefs seized control, 27-17.

Kansas City was about to turn the game into a route, marching to the San Diego 16 to start the second half. But Jahleel Addae snatched a deflected ball from the air and returned 90 yards for a touchdown. Suddenly, the Chargers trailed just 20-17, but they would get no closer.

Trying to force a ball into double coverage, Rivers set a career-high with his 21st interception -- corralled by Daniel Sorensen -- toward the end of the first half. The Chiefs stretched their lead to 20-10 off the turnover, as Cairo Santos kicked a 25-yard field goal.

Rivers threw the first of his two opening-half interception -- this one picked off by Marcus Peters -- and the Chiefs didn't waste the opportunity.

With about six minutes remaining in the half, Smith rolled to his right and connected with a wide-open West. The 4-yard touchdown gave the Chiefs a 17-10 cushion.

Smith ran around the left side for a 5-yard touchdown, knotting the score at 10-10 with 12:53 to play in the second quarter.

Gates carved his name in the NFL record book with his 2-yard, second-quarter touchdown that delivered a 10-3 Chargers' lead. Gates' reception marked his 111th career touchdown catch, tying him with Tony Gonzalez for the most by a tight end in league history.

The Chiefs, on their second series, pulled even with the Chargers at 3-3. Santos kicked a 35-yard field goal after the Chiefs had the ball at the San Diego 10. But a sack and tackle for a loss by Joey Bosa made Kansas City settle for three.

Lambo capped the Chargers' first possession with a 35-yard field goal.

NOTES: San Diego S Darrell Stuckey (knee) and LB Christopher Landrum (concussion) were injured in the first half and did not return. ... Kansas City OLB Justin Houston (knee) was out, replaced by Tamba Hali in the starting lineup. ... Chiefs RB Spencer Ware (ribs) was also unable to play. ... The Chiefs elevated LB Justin March from the practice squad. ... Kansas City DE David King was waived. ... Chargers LT King Dunlap (knee) was out. ... RB Melvin Gordon (hip, knee) didn't play and ended the season three rushing yards shy of 1,000. ... In potentially the final Chargers' game in San Diego, tickets were on sale for $33 on the secondary market.