Jordan Zimmermann halted a five-start winless drought when he faced Colorado in late June. The Washington Nationals hurler will try to extend his current winning streak to three straight starts in a rematch this afternoon as he closes out a three-game series with the Rockies.

Zimmermann broke back into the win column with an excellent effort in Colorado on June 27, hurling seven frames of one-run ball for his first win since May 22. He also kept his perfect record versus the Rockies intact, moving to 3-0 with a 1.96 earned run average in four starts.

The right-hander made it two victories in a row on Tuesday as he held the Giants to a pair of runs -- one earned -- on seven hits over six innings. He did not walk a better and struck out seven. Zimmermann also benefited by pitching from in front as the Nationals led 8-0 by the fourth.

"When they give you a lead like that you don't want to let them back in the ballgame," Zimmermann said. "I just went out there, threw strikes and pounded the zone."

Zimmermann, 26, improved to 5-6 with a 2.70 ERA in 16 starts this season and has pitched at least six frames in each outing.

Jeremy Guthrie goes for the Rockies after winning back a rotation spot with a solid outing earlier in the week versus the St. Louis.

After a demotion to the bullpen, the right-hander made his first start since June 17 on Wednesday and allowed two runs and six hits over six innings. Guthrie lost a 4-1 decision, but impressed manager Jim Tracy.

"That's the guy that pitched on Opening Day in Houston, the guy that pitched in Milwaukee, and they were seven-inning starts," Tracy said on Colorado's website. "He gave us a chance to win."

Guthrie did remain winless since May 31 and Colorado has lost each of the last eight games he has appeared in. That includes a relief stint versus the Nats on June 27 as he gave up three runs over four innings.

The 33-year-old is 3-8 with a 6.28 ERA in 16 games (12 starts) this season and 2-1 with a 2.34 ERA lifetime versus Washington.

The Nationals will head into the All-Star break atop the National League East, holding a 4 1/2-game lead over the Mets following yesterday's 4-1 win over the Rockies.

Gio Gonzalez picked up his 12th victory, matching Livan Hernandez for the most by a Nationals pitcher before the All-Star break, by giving up a run over six innings. His offense secured the victory with a three-run sixth frame, highlighted by Ryan Zimmerman's go-ahead RBI single.

"He didn't want to leave with the game tied," Washington manager Davey Johnson said. "I said, 'You're done. You're not talking me out of nothing and we'll get you a win right here.'"

The Nats have won six of their last eight.

Jeff Francis fanned five and was charged with three runs on six hits and a walk in five innings for Colorado, which has dropped six of its last eight contests.

"It was a tough game to lose," Francis said. "It was well pitched and made a couple mistakes at a bad time."

Dexter Fowler registered three hits, while Jordan Pacheco's sacrifice fly in the fourth accounted for the Rockies' lone run.

Colorado split a four-game set with the Nats earlier in the year.