OAKLAND, Calif. -- Marco Scutaro chalks up most of his game-winning hits to good timing. Oakland general manager Billy Beane called this one.
"I don't know, it's just good timing I guess," Scutaro said. "Billy told me before the game that I'd get the winning hit. I just got the opportunity. I'm not an RBI guy. I just try for good at-bats."
"I'm not really worried," Mussina said. "You've got to get to 100 pitches some time. I'll see how I feel tomorrow. Tomorrow and the next day will be the test to see how I come out of it."
Milton Bradley drew a leadoff walk in the ninth against loser Scott Proctor, then moved to second on Jason Kendall's sacrifice. Swisher was intentionally walked to bring up Scutaro, playing in place of injured shortstop Bobby Crosby.
It was Scutaro's sixth game-ending hit during three seasons with the A's. He has five singles and a home run. Scutaro raised his right arm in the air in celebration, then hit his fist on his chest before being hugged by teammates.
The A's turned to closer and reigning AL Rookie of the Year Huston Street (1-0) to start the ninth and he escaped unscathed after allowing Johnny Damon's one-out double. It began raining after Gary Sheffield walked with two outs in the inning.
Jorge Posada hit a go-ahead single in the sixth and drove in another run on a groundout a night after he was the lone New York starter without a hit in Monday's season-opening 15-2 rout of the A's.
Chavez hit the first pitch he saw in the sixth over the right-field wall to tie the game at 3.
It was a tough night for Proctor, who rejoined the team Monday after returning home to Miami for four days to be with his wife and newborn daughter, who had surgery to repair the aortic arch in her heart.
"I felt fine to go today," Proctor said. "There's no excuse for not getting it done."
His teammates and manager know the Yankees had plenty of opportunities to win, and didn't blame the loss on Proctor.
"I think he certainly understands his responsibility," manager Joe Torre said. "More than anything, it was the fact that he hadn't pitched more so than the mental aspect."
A's right-hander Rich Harden made his first start since last Aug. 19 after being sidelined for more than a month with a strained muscle in his upper back below his throwing shoulder. He made three relief outings in September and finished with 10 wins in 19 starts. He spent time on the disabled list earlier in the season with a strained left oblique muscle.
The 24-year-old Harden allowed three runs and seven hits in 5 2-3 innings, struck out four and walked four in a 103-pitch outing.
The teams were happy to get the game in after a heavy rainstorm drenched the area overnight and for most of the day -- avoiding a day-night doubleheader on Wednesday that had been the contingency plan if the weather didn't cooperate.
Alex Rodriguez singled twice, grounded out and struck out twice a night after hitting a grand slam and getting five RBI in Monday's victory. He struck out to end the seventh with Damon on second.
"When you have so many different opportunities and can't deliver the big hit, you get an 'L,"' Rodriguez said. "That was the big difference between yesterday and today. Yesterday we delivered the big blow."
A-Rod bounced his batting helmet to the dirt after trying to stretch a single into a double and getting caught in a rundown to end the third with Sheffield in scoring position. With runners on second and third in the first, Harden struck out Sheffield, Rodriguez and Jason Giambi in succession.
"That's not what I wanted to do in my first start and my first inning," Harden said. "I was a little excited and just needed to get through that. I threw too many pitches and that killed me later in the game. I had nothing left at the end of the game."
Frank Thomas drew a one-out walk in the sixth, marking the first time Oakland's new designated hitter had to run the bases in spring training or the regular season -- excluding his 449th career home run Monday. The 37-year-old Thomas missed all but 34 games last season with the White Sox because of separate left ankle fractures.
Mussina retired the first seven A's hitters before Swisher's homer in the third. Mark Kotsay hit an RBI single three batters later to give the A's a 2-1 lead.
Mussina, a 13-game winner last season, plunked Kendall leading off the seventh, Kendall's 198th hit by pitch to tie him with Frank Robinson for seventh on the career list.
- The Yankees were 1-for-15 with runners in scoring position.
- Derek Jeter doubled in the first and raised his lifetime batting average against Harden to .462 (6-for-13)
- Crosby is expected to miss about a week with a bruised and cut index finger on his left hand sustained when Robinson Cano spiked him sliding into second Monday.