In Oakland, Bret Saberhagen pitched a three-hitter and Hal McRae hit a two-run home run to carry Kansas City to its fourth straight victory and 12th in 13 games.
Saberhagen (18-6), winner in 16 of his last 19 decisions, struck out a career-high 12, walked two and retired the final 11 batters he faced in outdueling Oakland starter Tommy John, who gave up five hits in eight innings.
"He's good now but he's getting better," Royals catcher Jim Sunderg said of the 21-year-old Saberhagen. "It's almost scary to think how good he'll be when he's been around a few years."
A's Manager Jackie Moore, who was ejected in the fifth inning by home plate umpire Greg Kosc for arguing a called strike, also was impressed by Saberhagen.
"If there's a better right-handed starter in the league this year, I don't know who he is," Moore said. "He threw every pitch to the exact spot he wanted."
After George Brett reached on second baseman Mike Gallego's one-out sixth-inning fielding error, McRae homered off (4-8) John.
The A's came back in the bottom of the sixth as Tony Phillips doubled to score Alfredo Griffin, who had singled and stolen second.