SEATTLE - Marlon Byrd caught himself mid-sentence. He wasn't about to portray any doubt.

"I'm hoping we're going to put together a run. Actually, I'm not hoping. I know we're going to put together a run before the All-Star break," the Cubs center fielder said after driving in the tiebreaking run in the 13th inning of a 3-2 win over the Seattle Mariners on Thursday.

It's a refrain Cubs' fans have heard for much of the subpar season. They can only hope Thursday's victory and a weekend series against the rival White Sox can be the starting point for the run Byrd said he knows is coming.

On an afternoon where both teams struggled to come up with a clutch hit, Byrd finally came through with a single off Seattle reliever Sean White to help Chicago avoid a sweep. Alfonso Soriano walked to lead off the 13th against Garrett Olson (0-2) and didn't hesitate at third, scoring ahead of Ichiro Suzuki's throw.

While the Cubs were able to salvage a game against the equally underperforming Mariners, it's the next 10 games that hold major importance. After facing the White Sox, the Cubs have seven straight at home.

"Right now we're a team trying to figure out how to win and now we have to go in there and try and win the series," Byrd said. "It's series after series, you just can't win one."

John Grabow (1-3) pitched two innings of relief for the win. He gave up just one hit in his first victory since May 24, 2009, for Pittsburgh, and Chicago's bullpen tossed seven innings of relief, giving up just one run and six hits.

Tom Gorzelanny got the final out of the 13th inning for his first career save.

"I like starting more. Closing is a little too stressful," Gorzelanny said. "There is a lot of pressure for just three outs."

The Cubs victory snapped Seattle's six-game winning streak and spoiled another stellar performance by young right-hander Felix Hernandez. But Seattle failed to capitalize on multiple opportunities to hand Hernandez his sixth win of the season.

The Mariners left 13 runners on base and were 3 for 16 with runners in scoring position.

"The key for me is the amount of strikeouts. We had 10 strikeouts with runners on base and that just can't happen," Seattle manager Don Wakamatsu said.

Mike Fontenot drove in Chicago's first run with a sacrifice fly in the third and Chad Tracy gave the Cubs a 2-1 lead in the seventh with an RBI single.

Jack Wilson hit an RBI double in the bottom half off reliever Andrew Cashner to tie it 2-all.

It was the continuation of a strong month by Hernandez. Recovering from a 2-4 start to the season, Hernandez has now thrown at least eight innings on five of his last six outings. He tossed a complete game last Saturday against Cincinnati, giving up just one run and five hits.

He nearly matched that on Thursday. Hernandez scattered five hits, struck out eight and allowed just the two runs.

Closer David Aardsma came on for the 10th inning and immediately walked Tracy on four pitches. Pinch-runner Starlin Castro reached third with two outs, and Aardsma got Theriot to fly out to end the threat.

Seattle missed on another great chance in the bottom half. Chone Figgins led off with a four-pitch walk from Cubs closer Carlos Marmol, who got Suzuki for the final out of the ninth. Marmol walked Mike Sweeney, but recovered to get Jose Lopez swinging at strike three in the dirt for the first out.

Figgins was then at the front end of a double steal and was called safe by third base umpire Mike Reilly on a close play. That brought Lou Piniella out of the Cubs dugout. Piniella barked at Reilly, taking off his hat and seeming on the verge of getting ejected before returning to the dugout.

After Franklin Gutierrez was intentionally walked, Marmol struck out Josh Wilson and Eliezer Alfonzo, both on wicked sliders, to end the threat.

"I certainly had a big one with the bases loaded and couldn't put the ball in play. That hurts," Josh Wilson said. "Winnings teams score that run right there and win."

Cubs starter Ted Lilly threw six strong innings, but his day was cut short by a high pitch count. Lilly surrendered just one run, five hits and struck out six.