BALTIMORE -- After Jarrod Parker and Chris Tillman waged a magnificent pitching duel for eight innings, it became apparent that a tense matchup between the Oakland Athletics and Baltimore Orioles was going to be decided by each team's bullpen.

Coco Crisp had a say in the matter, too.

Crisp hit a tiebreaking homer off Darren O'Day leading off the ninth, providing Oakland with a 2-1 victory Saturday and handing Parker his eighth straight win.

Parker (10-6) gave up one run, five hits and three walks to improve to 8-0 in 16 starts since May 22. The right-hander threw 117 pitches and worked out of jams in the sixth and eighth innings.

When he walked off the mound for the last time, Parker knew he was done. Instead of retreating to the clubhouse, he watched as Crisp lined a breaking ball from O'Day (5-3) over the right field wall.

"It's gratifying that the guys are just able to pick you up," Parker said. "It's one of those things where it almost seems like it's meant to be when it happens."

Maybe it was. Crisp thought he'd received ball four earlier in the at-bat. He ended up trotting around the bases rather than jogging to first base.

"Tried to bunt, tried to walk, and I was still in the at-bat and I was able to get a pitch," said Crisp, who has homered in each of his last three games.

Asked if he'd like to have that pitch back, O'Day said, "I'd like to have all of them back to him. I got behind in the count and he was looking for his pitch. I've got to be ahead in the count, so yeah, he got what he wanted and he did what he wanted with it."

Oakland manager Bob Melvin had no intention of sending Parker back out in the ninth. So he called upon closer Grant Balfour, who got three straight outs for his 32nd save.

"There's no doubt he's done," Melvin said of Parker. "Good thing there are pitch counts. Both of those guys, that game might have gone on for a while. Both those guys were dominant today. It usually takes one swing of the bat, defensive play, whatever, and it was Coco's late. It was good to reward Jarrod because, boy, he pitched about as good as you can pitch."

So did Tillman, who allowed one run, three hits and two walks but remained winless since Aug. 2. His nine strikeouts tied a career high, set earlier this month in San Francisco.

"Tilly bent but didn't break a couple times," manager Buck Showalter said. "It's frustrating. We end up on the losing side, but watching two guys at the top of their craft matching each other, you knew there was going to be a fine margin of error."

Kurt Suzuki doubled and scored a run in his first game back with Oakland after being traded from Washington on Friday. The victory broke a three-game skid for the A's, who improved to 16-17 since the All-Star break and solidified their hold on the second and final AL wild-card slot.

Ryan Flaherty homered for the Orioles, who have lost seven of 11.

"In the playoff race, it's important. Every game is important," Tillman said. "A loss always stinks. They're never fun."

Parker retired the first seven batters he faced before Flaherty hit his first home run since Aug. 2. Six of his eight homers have been solo shots.

Oakland didn't get its first hit until Jed Lowrie singled with one out in the fourth.

Tillman didn't allow another baserunner until Suzuki doubled to left with one out in the sixth. He advanced on a groundout and scored on double by Lowrie.

Manny Machado began the Baltimore sixth with his major league-leading 44th double. With two outs and runners at the corners, Nick Markakis hit an opposite-field fly to left that was caught on the warning track.

The Orioles got runners at first and third with two outs in the eighth before Matt Wieters grounded out to shortstop.

Game notes
Twelve of Crisp's 13 home runs have been solo shots, and nine have put the A's ahead. ... Athletics RHP Bartolo Colon (strained left groin) will throw a bullpen session Monday when the team goes to Detroit. Colon was placed on the 15-day disabled list Aug. 17 when he hurt himself throwing on flat ground. ... Scott Feldman (3-3) makes his ninth start for Baltimore in the series finale Sunday. Sonny Gray will pitch for the A's. He has allowed four hits or fewer in each of his first three career starts.