Edwin Jackson may not be the ace of Washington's staff, but he has pitched like one for most of the season.

Jackson looks to extend an impressive run of starts this afternoon and hurl the Nationals to a series win over the Colorado Rockies in the finale of a four-game series.

The right-hander has won three of his past four starts and hasn't allowed more than three runs in nine consecutive outings. He took a perfect game into the fifth inning on Saturday versus the Orioles and ultimately won a 3-1 decision after allowing a run on four hits and a walk.

Jackson improved to 4-4 with a 2.91 earned run average through 14 starts this season and said afterwards that he approaches every day he pitches like he's the No. 1 starter.

"You have to be No. 1 on the day you pitch regardless of who you're pitching against," he said. "Numbers are numbers."

The 28-year-old hasn't looked like an ace over his career when facing the Rockies, who he is 1-2 against in six starts with a 13.91 ERA. Jackson has yielded 34 earned runs and five homers in 22 innings in this matchup, including 21 runs in just 12 frames over three starts at Coors Field.

Josh Outman looks to earn his first victory of the season today for the Rockies, having made five straight starts after spending time in the bullpen. He is 0-2 as a starter with an 8.41 ERA and has completed five innings only once in that span.

The 27-year-old southpaw was charged with five runs on eight hits and a walk in 4 2/3 innings of a no-decision at Texas on Saturday, throwing 92 pitches. With manager Jim Tracy going with a four-man rotation and trying to keep his starters to a 75-pitch limit, he opted to push Outman's next start back from yesterday to today.

Outman will face the first-place Nationals for the first time in his career.

After losing the opener of this series on Monday, the Nationals have pounded out a pair of wins to even their record on a 10-game road trip. Washington plated a season-high 12 runs and 21 hits in Tuesday's victory, then notched another 14 hits in last night's 11-5 triumph.

Six Nationals recorded multi-hit games, including Ryan Zimmerman and Jhonatan Solano, who both drove in three runs. Zimmerman, Ian Desmond and Tyler Moore all homered to overshadow a solid performance by starter Jordan Zimmermann.

"I don't think anybody here is really searching for confidence. We know we can play," said Desmond. "We've been playing good baseball all year long. It's nice to see the bats turning around."

Zimmermann snapped a five-start winless stretch by scattering eight hits and three walks in seven innings of one-run ball.

His counterpart, Edwar Cabrera, failed to make it out of the third inning in his first career start, as the 24-year-old lefty was touched for seven runs -- five earned -- on five hits and three walks.

Washington improved to 3-3 on a 10-game road trip and dropped Colorado to 4-16 since June 5.

The Rockies scored four runs over the final two innings off Washington's bullpen. Tyler Colvin, Jordan Pacheco, Dexter Fowler and Marco Scutaro each drove in a run

"It is encouraging. We're definitely built to hit," Colvin said about the Rockies' late-game rally. "It's one of those things where you just have to stay in the game, keep plugging away and scoring some runs."

The Rockies have won eight of their past 13 versus the Nationals.