Oakland, Calif. ? The last time Trevor Cahill tossed a complete game, he had just committed to Dartmouth and was still a few credits short of his high school diploma.

These days, he’d have been the odd man out if he didn’t finish the game.

Cahill tossed the Athletics’ third straight complete game and his first in the big leagues, Rajai Davis hit a two-run homer and Oakland beat Kansas City, 3-0, Monday night to end the Royals’ three-game winning streak.

“He’s an All-Star,” Davis said, “and it was another typical All-Star performance by our All-Star. It’s pretty amazing, isn’t it?”

Cahill (11-4) used his sinker to get out of trouble, and only Wilson Betemit advanced as far as second when he led off the eighth with a double. Betemit was stranded there, one of only two Royals left on base during Cahill’s three-hitter.

“The sinker is the key to my success all the time,” he said. “I was able to keep it down in the zone. I walked a few guys but I also caught a break and got the double plays.”

Matt Watson, Kevin Kouzmanoff and Coco Crisp also drove in runs for the A’s, who won their fifth game of the last six played at home. Mitch Maier and Chris Getz collected the other hits for the Royals, who were shut out for the first time since July 4 and the fifth time overall.

Dallas Braden beat the Chicago White Sox on Saturday to start the A’s run of complete games, and Gio Gonzalez lost on Sunday while finishing up. It’s the first time Oakland has had three in a row since Sept. 8-10, 2000, when Gil Heredia, Tim Hudson and Barry Zito accomplished the feat.

“I was happy,” Cahill said. “We’re all kind of building on each other.”