Guillermo Moscoso carried a perfect game into hitter into the eighth, but had to settle for 0 win over Kansas City.
Moscoso lost his perfect game on a four-pitch walk in the sixth inning, the first time a Royals hitter even saw as many as three balls, and he watched his no-hit bid end on Salvador Perez's two-out single in the eighth.
Although history eluded him, the right-hander has never been better.
Moscoso (8-8) worked into the ninth inning for the first time in 18 career major league starts, but was lifted by Athletics manager Bob Melvin with two runners in scoring position and two outs, also losing his chance to pitch his first career complete game.
"It can be a tough job sometimes," Melvin said of removing his starter. "I'm close to Mo-Mo and I've gotten to know Mo pretty well here this year. He's a fighter, he's a tough kid. There's guys with better stuff, but I don't know if there's too many with a bigger heart. It was difficult to have to take him out."
His bid to throw the seventh no-hitter in Oakland history was broken up when Perez lined a 2-2 pitch into right field. Earlier, Alcides Escobar was the first Royal to reach base in the sixth inning when he took a close pitch for ball four, drawing a two-out walk.
In the end, Moscoso was charged with two hits and a walk while striking out four. He threw 86 of his 129 pitches for strikes.
"You always want to go deep in games," Moscoso said. "You always want to have great outings like I did today. You never know what's going to happen."
Fautino De Los Santos came in and threw one pitch in relief of Moscoso, getting Eric Hosmer on a pop out to end the game.
The A's banged out 13 hits in support of their starter and bounced back from losses in the first two-games of this three-game series. Moscoso, 27, earned a decision in his eighth straight start (5-3).
The A's have two perfect games since moving to Oakland, including Dallas Braden's last season on Mother's Day.
Moscoso's bid for No. 3 was intact through 5 2/3 innings. In the third inning, right fielder Michael Taylor tracked Perez's fly ball into foul territory only to watch it pop out of his glove. But Taylor recovered, wrangling the ball back for the first out.
Fans booed home plate umpire Hunter Wendelstedt in the sixth when called a borderline pitch ball four to Escobar. Moscoso recovered to get Alex Gordon on a fly ball three pitches later.
In the eighth, after Jeff Francoeur hit a sharp liner that was snared by Weeks at second base for the first out, Wendelstedt rung up Mitch Maier on a fastball that looked to be a little high and outside.
Perez recovered from an 0-2 count to single on a 2-2 pitch, breaking up the no-hitter.
"It kind of sucks when you're cheering for one hit and that's the most exciting play of the day. At least we didn't get no-hit," Gordon said.
Besides Braden, Oakland has thrown five other no-hitters, including Dave Stewart's in 1990 and Mike Warren's in 1983. Four pitchers -- Vida Blue, Glenn Abbott, Paul Lindblad and Rollie Fingers -- combined on a no-hitter in 1970 and Catfish Hunter threw a perfect game in 1968.
Chen was charged with six runs -- five earned -- on eight hits and three walks. He struck out two and lost his second straight start on the heels of a personal five-game winning streak
Kurt Suzuki hit a two-out single in the fourth and scored from first base when Gordon dropped Taylor's long drive on the warning track in left-center field.
Sizemore hit a two-run double in the fifth to make it 4-0 and Oakland finished the scoring with a three-run sixth, highlighted by Weeks' RBI double and Hideki Matsui's run-scoring single.
The A's won the season series 5-4...The Royals opened a seven-game road trip in Oakland that will continue with a four-game series in Seattle starting Thursday...No surprisingly, most of the game moved at a brisk pace and it was over in 2 hours and 41 minutes.