OAKLAND, Calif. (AP) – Brian Roberts scored the go-ahead run in the seventh on a controversial error, and the Baltimore Orioles won in wild fashion for the second straight game with a 4-3 victory over the Oakland Athletics on Tuesday night.

Rafael Palmeiro, facing constant boos in his second game back in the lineup following a 10-game steroid suspension, had a double and a single and scored a run.

Just as they did a day earlier, the A’s fell apart in the seventh with a costly mistake – and Oakland lost three straight for the first time since being swept at Washington from June 7-9. The Orioles rallied for five runs in the seventh inning of their 6-2 win Monday night, taking advantage of two hit batsmen, two bases-loaded walks and an error.

This time, Baltimore scored three unearned runs in the seventh against Jay Witasick (1-1). With two outs, Melvin Mora hit a sharp grounder to third and Eric Chavez had to dive to make the stop. He threw a one-hopper to first baseman Dan Johnson, who had to come off the base to field the ball but appeared to get his heel back in time.

But first-base umpire Chris Guccione signaled that Johnson’s foot was off the bag. Replays from several angles showed he touched the base. A’s manager Ken Macha rushed out to argue to no avail.

Bruce Chen (10-6) took a four-hitter into the seventh inning and won his third straight start after going winless in his previous five outings. The left-hander went 1-2-3 in the second, third and fifth innings and was only threatened in the fourth. He struck out three and walked one in 6 2-3 innings. B.J. Ryan escaped a difficult ninth for his 27th save in 32 tries.

Ryan loaded the bases with one out on singles by Johnson and Bobby Kielty and a walk to Mark Ellis. Jason Kendall hit a sharp infield single that shortstop Miguel Tejada struggled to field, then Mark Kotsay flied out to left and Eric Byrnes made a strong throw home to save a run. Bobby Crosby struck out looking to end it.

The A’s tied the game on Kotsay’s solo homer to right leading off the sixth, his 11th of the year, and he also had an RBI single in the eighth.

Oakland loaded the bases with one out in the fourth. Jay Payton then flied out to left and former A’s outfielder Byrnes made a strong throw home that sailed over catcher Javy Lopez, but Chen was there backing up and a run didn’t score.

Scott Hatteberg then grounded into a force out and Chen got out of the inning unscathed.

Palmeiro was booed loudly when announced in the starting lineup, then received the same treatment during his first at-bat in the second and every other time he came to the plate after that. It was the second game he’s played since returning from the suspension, which took effect Aug. 1 for violation of Major League Baseball’s new steroids policy. Palmeiro, expected to start at first base this weekend at Cleveland, doubled to left leading off the fourth for his first hit in six at-bats since being activated last Thursday. He scored moments later on Sammy Sosa’s RBI single to right for a 1-0 Baltimore lead.

Joe Blanton, making his first career appearance against the Orioles, loaded the bases in the second, but struck out Roberts to escape the jam.

Byrnes, playing his first series against his former team since being traded last month, is 0-for-9 so far in the series.

Notes: The A’s 6-2 loss Monday ended their 10-game home winning streak against the Orioles. … Baltimore grounded into double plays in the fourth and fifth innings. … Orioles RHP Sidney Ponson, on the disabled list with a strained right calf, threw a bullpen session and still experienced some soreness in the leg. Manager Sam Perlozzo doesn’t expect Ponson to come off the DL when he’s eligible. He will throw again Friday before the team determines the next step – though he might pitch in relief at least at the beginning once he’s back.

AP-ES-08-17-05 0103EDT