KANSAS CITY, Mo. (AP) Alex Smith had every reason to celebrate the Kansas City Chiefs' season-opening win over San Diego, starting with the fact it came after the biggest comeback in franchise history.
He had plenty of things to lament, too.
The Chiefs' offensive line got pushed around for three quarters, the defensive line was just as bad, and their secondary couldn't keep up with the Chargers' fleet of speedy wide receivers.
''I think everyone knows how bad we played,'' Smith said after the 33-27 overtime victory. ''As great as it is to win, there's going to be a lot to improve upon, a lot to learn from.''
The same goes for San Diego.
The Chargers raced to a 24-3 lead early in the second half, and still led 27-10 early in the fourth quarter. But Philip Rivers and Co. were unable to keep drives alive, Smith and the Chiefs capitalized on good field position, and the game was soon tied at 27 as regulation came to an end.
San Diego never even got a chance in overtime.
Smith marched the Chiefs downfield in 10 plays, then scampered into the end zone on third-and-goal from the 2. The touchdown completed their stunning comeback - and the Chargers' equally stunning collapse.
''You got to give them credit. They had an awesome fourth quarter and we didn't do anything to counter it,'' Rivers said. ''All of a sudden you look up and they're in overtime.''
As both teams begin digesting a wild season opener, here are some of the key takeaways:
ALLEN'S INJURY: The Chargers could be without wide receiver Keenan Allen the rest of the season after his knee buckled while making a cut in the second quarter. Allen had to be taken from the field in a cart, and coach Mike McCoy uttered the dreaded three-letter acronym ACL after the game.
''We're going to run further tests,'' he said. ''The way we've been doing it, the majority of teams, put a general statement out and when we get back home we'll further evaluate things.''
Allen had six catches for 63 yards before going down, and looked to be every bit recovered from the lacerated kidney that forced him to miss the final eight games last season.
''It's hard,'' McCoy said. ''Keenan has worked so hard to get where he is.''
CHIEFS CHURNING: Even without running back Jamaal Charles, who continues his own comeback from an ACL injury, the Chiefs were able to run their usual offense with backup Spencer Ware.
The bruising back not only ran for 70 yards, including the tying touchdown with just over a minute left in regulation, he also caught seven passes for 129 yards - one of them in overtime.
''He has a knack for making plays when you need them,'' Chiefs coach Andy Reid said.
CATCHING KELCE: The star of E!'s reality TV show about a search for love, Chiefs tight end Travis Kelce reminded everyone that he's a football player first. He had six catches for 74 yards, picking up a crucial third down that kept the winning overtime drive alive.
GORDON WAS GOOD: Melvin Gordon ran for the first two touchdowns of his career Sunday. The Chargers' first-round pick a year ago was a relative disappointment, never once getting into the end zone during his rookie season, but finally showed flashes of what made him a college star.
Not that he wanted to dwell on his performance: ''We have to watch the film and look at every play and analyze what we could have done better,'' he said. ''Today wasn't enough.''
WHAT A RUSH: The Chiefs managed one sack without star pass rusher Justin Houston, out after knee surgery in February. Some of that had to do with an improved San Diego offensive line anchored by new center Matt Slauson, which spent three quarters pushing around the Kansas City defense.
''We got into a nice rhythm,'' Chargers offensive tackle Joe Barksdale said, ''but you just can't let them back in. At the end of the day, we've got to close it.''
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