OAKLAND, Calif. -- Manager Bob Geren walked to the mound after Trevor Cahill issued his first walk of the game with one out in the eighth inning, making sure his starter still had enough left in the tank.
Cahill persuaded Geren to keep him in the game to the delight of the Oakland crowd and capped another strong start by retiring the final two batters of the inning.
Cahill allowed one run in a career-high eight innings to win his fourth straight start and the Athletics beat nemesis Ervin Santana and the Los Angeles Angels 6-1 Thursday.
"I just wanted to make sure he was OK," Geren said. "I wanted to see the look on his face and the reaction to the questions I asked him. I knew pitch count wise he was fine. The weather was just right. I felt like he was OK."
Cahill (5-2) was more than that, allowing only an RBI single from Bobby Wilson in the fifth while extending his run of strong starts. Cahill gave up six hits and one walk, lowering his ERA to 1.33 in his past four starts.
He got a standing ovation from the crowd of 12,328 when he finished, topping the 7 1/3 innings he pitched last year against Arizona.
"It was pretty cool," he said. "We don't have the biggest crowds so when they're into the games like that it shows they're paying attention. It was pretty special."
Ryan Sweeney scored three times and Daric Barton drove in one run and scored two for the A's, who earned a split of the four-game series against their AL West rivals.
Andrew Bailey finished with a perfect ninth, sending the A's into an interleague series in San Francisco against the cross-bay rival Giants on a high note.
The A's struck for two runs in the fourth and three in the fifth against Santana (6-4), who came into the game with an 11-2 record and a 1.50 ERA in 19 career appearances against Oakland. His ERA was the lowest any pitcher with at least 10 starts had against the A's and he had never given up more than three runs in a single start.
"I made a couple mistakes but that doesn't really matter because I have to refocus and just pitch," Santana said. "That's going to happen a lot. Nobody's perfect."
The Angels finish their 14-game road trip with a three-game series in Los Angeles against the Dodgers. They are 8-3 so far on the trip.
Santana, who had won five straight starts, retired the first eight batters he faced and appeared to be in control once again until issuing a leadoff walk to Barton to open the fourth inning. Sweeney followed with an RBI double that right fielder Juan Rivera appeared to misplay and Gabe Gross drove in another run with a swinging bunt single with two outs.
"Guys were just getting good pitches to hit up in the zone and taking advantage of it," Sweeney said. "We didn't try to do too much. We scored quite a few runs off him today which was good."
The A's added three more runs in the fifth on RBI singles by Barton, Kurt Suzuki and Kevin Kouzmanoff to make it 5-1. Cliff Pennington scored the first run after his second single in the game. Pennington had been mired in a 3-for-46 slump before coming through against Santana.
Santana allowed five runs -- four earned -- and seven hits in five innings -- his shortest start of the season.
"Ervin wasn't that far off. Those guys did a good job when they got some guys in scoring position," manager Mike Scioscia said. "I certainly don't think he pitched as poorly as maybe his linescore is going to show."
The A's improved to a major league best 16-7 in day games. ... The Angels had been 7-0 when Wilson started at catcher. ... Suzuki will miss the three-game series against the Giants because of a death in the family. The A's will call up a catcher to replace him while he is on bereavement leave. ... Geren will miss the opener Friday to attend his son's high school graduation. ... Oakland DH Eric Chavez (neck spasms) will begin a rehab assignment at Triple-A Sacramento on Monday. ... A's OF Rajai Davis (left hamstring) ran before the game and is expected to return this weekend in San Francisco, Geren said.