SEATTLE (AP) - The Texas Rangers missed two key players along with the opportunity to gain a game in the tight AL West race.

Carlos Triunfel drove in the tiebreaking run in the fourth inning and Miguel Olivo hit a two-run homer in the eighth to lead the Seattle Mariners to a 6-3 victory over the Rangers on Friday night.

Hisashi Iwakuma (7-5) held the Rangers to three runs and eight hits in seven innings, and Justin Smoak had three hits and scored two runs for the Mariners.

Tom Wilhelmsen worked the ninth to pick up his 28th save in 32 opportunities.

The Rangers were without third baseman Adrian Beltre (stomach) and outfielder Josh Hamilton (sinus/blurred vision). Beltre should be available Saturday, while Hamilton is out for the weekend series while undergoing tests back in Dallas.

"We're not making it easy on ourselves when two guys like that aren't in the lineup but we have plenty of depth," said David Murphy, who had three hits and all three RBI. "We're still going to battle offensively and do whatever we can to scratch runs across.

"Those are our horses. Between them they have 70-something home runs and 200-plus RBI. It hurts but we're not at the point in the year when we can sit back and dwell on that. We have to keep playing good baseball and keep nailing down wins."

Mariners center fielder Franklin Gutierrez, who had a triple and scored a run, said without Hamilton and Beltre "those guys look a lot different. Those guys make a lot of difference on that team."

Texas remains four games ahead of Oakland in the division with 12 games remaining. The A's lost 2-1 in 10 innings against the New York Yankees.

"We want to win every day. Just the fact they lose doesn't mean it's a must-win situation," Murphy said. "It would have been nice to shave another game off that (magic number) but bottom line is we're just playing for wins. We're not worried about what they're doing."

Texas starter Martin Perez (1-2) gave up three runs and six hits in four innings. He struck out three, walked two and threw two wild pitches.

It was even more frustrating for the Rangers because they gave a little help to the Mariners, who scored one run on an error by Michael Young and another on one of Perez's wild pitches.

The Rangers tied the score at 2 in the fourth. With one out, Young singled to right and advanced to third on Nelson Cruz's doubled to left, and both scored on Murphy's single to center.

The Mariners regained the lead in the bottom of the inning. Triunfel's double down the left-field line scored Casper Wells all the way from first to put Seattle ahead 3-2.

"That was one of those things," said Young, as he watched the ball bounce over his head. "He made a good pitch and they caught a break right there, a trampoline ball and it worked out well."

Triunfel moved to third on a fielder's choice and scored when Young booted Gutierrez's grounder.

"He hit it hard but it was a routine play," Young said. "I should have come up with that."

Murphy made in 4-3 in the sixth with his 14th homer, and Olivo's shot off Alexi Ogando in the eighth capped the scoring.

Smoak doubled off Perez to open the second inning. It was the first hit Perez yielded to the Mariners in 6 1-3 innings, covering three appearances.

Michael Saunders drew a walk. With one out, Wells lined a double into the left-field corner, scoring Smoak and sending Saunders to third. That broke a 0-for-23 streak with runners in scoring position.

The Mariners added a run in the third as Gutierrez legged out a triple that bounced off the top of the center-field wall and scored on Perez's wild pitch.

"It was a sinker too hard for the catcher to block," Perez said. "If I happen to throw in the glove, it's different."

Olivo gave Wilhelmsen breathing room in the eighth with his 12th home run off Alexi Ogando.

"A couple plays there and we'd have stayed in the ball game, even though Perez was not at his best," Rangers manager Ron Washington said. "We were in it 'til Ogando hung that slider to Olivo."

Murphy, who fell a triple short of the cycle, added, "it would have been nice to see what would have happened if it was 4-3 in the ninth, to see if could have done anything."

NOTES: Beltre and Hamilton have combined for 76 home runs, 189 runs and 218 RBIs this season. ... Young, who extended his hitting streak to 10 games with a fourth-inning single, now has 257 career hits against Seattle. That's second all-time behind Cal Ripken Jr.'s 261. ... Mariners 2B Dustin Ackley left the game in the fourth inning with a stiff neck. ... The Seattle baseball writers' chapter voted Felix Hernandez and Kyle Seager for the Mariners MVP awards for pitcher and hitter, respectively. John Jaso was given the Unsung Award. Also, the MLBPAA awarded the Heart and Hustle Award to SS Munenori Kawasaki.