OAKLAND, Calif. (AP) -- Gil Heredia isn't thinking about the ERA title yet. He just wants to stay consistent.

Heredia (5-2) won his fourth straight decision despite leaving with a hamstring injury and the Oakland Athletics defeated the Seattle Mariners 7-2 Sunday.

	Oakland's Jason Giambi leads the majors in both home runs (16) and RBI (46).

Jason Giambi hit his major league-leading 16th home run and drove in three runs to increase his total to 46, also tops in baseball, as the A's moved back into first place with their fifth win in six games.

"I'm just getting good pitches to hit," Giambi said. "I came into camp a little stronger, but it just comes down to seeing better pitches."

Heredia allowed two runs and seven hits in 5 2/3 innings and is fourth in the AL with a 2.52 ERA.

"I take great honor in that, but statistics are so overrated," Heredia said. "If I'm successful and consistent and we're winning games, that's what counts. If this were the end of the season, then yeah, obviously, I'd have something to say."

Heredia was hurt covering first base on Alex Rodriguez's infield hit in the sixth. He reached for a throw from Giambi and faced two more hitters before leaving with tightness in his right hamstring.

"First of all, I was late covering and it was my fault," said Heredia. "It was just a little cramp. It was more precautionary than anything."

Paul Abbott (1-1) lasted four innings in his second start of the season, giving up seven runs, five hits and six walks.

"I was struggling all day," Abbott said. "I was brutal."

Seattle, which walked 10 A's, has lost five of seven.

"You don't win many games with 10 walks," Mariners manager Lou Piniella said.

In a game that started 1 hour, 22 minutes late because of rain, Miguel Tejada's fourth homer gave Oakland a 2-0 lead in the second.

Matt Stairs and Jeremy Giambi each drove in a run in third, then Jason Giambi homered into the right-field stands in the fourth.

Heredia stranded four runners in the first five innings before running into trouble following his injury.

Edgar Martinez doubled home a run to end Heredia's day, and Doug Jones gave up a run-scoring single to Jay Buhner.

Game notes
Mariners reliever Jose Mesa has a 6.55 ERA at home; it's 2.77 on the road. ... The A's lead the majors in runs (108) and walks (85) in May. ... Rodriguez's infield single in the fifth gave him a 10-game hitting streak.