ESPN MLB

WASHINGTON -- Carlos Gonzalez appeared to be out on a caught foul tip, ending Colorado's half of the fifth inning in a scoreless game Thursday night.

At least that's what the home-plate umpire thought. That's what Washington starter Garrett Mock thought, too. So did his teammates, who started jogging off the field.

Second-base umpire Doug Eddings saw things differently. Eddings realized that Gonzalez's bat touched the ball, which then skipped off the dirt before landing in Nationals catcher Josh Bard's glove. As replays showed, it was merely an innocent foul ball, not a third out.

Given a chance to stay at the plate, Gonzalez blooped an RBI double down the left-field line that sent the Rockies on their way to a 4-1 victory, completing a three-game sweep.

"I don't know how Dougie saw that play out there," Nationals center fielder Nyjer Morgan said. "I guess he was eating his carrots today."

Gonzalez's club record-tying streak of four games with a homer ended, but he again came through for the NL wild-card leaders. Troy Tulowitzki and Brad Hawpe also drove in runs to back a strong performance by Jason Hammel (8-7), who allowed one run and three hits in seven innings.

Huston Street worked a perfect ninth for his 32nd save in 33 chances, including every game this series.

Colorado has won four consecutive games and eight of 11. The Rockies entered the day 3 1/2 games behind the Los Angeles Dodgers in the NL West.

"Why should our sights only be set on the wild card? Play, and see what happens," Rockies manager Jim Tracy said. "Let's go for the division."

It's been a far more successful week off the field than on it for last-place Washington, which promoted acting general manager Mike Rizzo to the full-fledged GM job Thursday. The club also signed No. 1 overall draft pick Stephen Strasburg on Monday, and plans to introduce the hard-throwing right-hander to its fans at Nationals Park on Friday.

Seeing Gonzalez play so well this series -- he homered Tuesday and Wednesday -- must have been bittersweet for Rizzo: He spoke Thursday about scouting Gonzalez in a cow-filled field in Venezuela while working for the Arizona Diamondbacks.

Indeed, Rizzo, Gonzalez and Mock all were part of the Diamondbacks organization in the past. The Rockies had two runners on base with two outs in the fifth when Mock (2-5) and Gonzalez squared off against each other on this night.

Mock appeared to get out of trouble when Gonzalez swung at a pitch and the ball wound up in Bard's mitt. But Tracy questioned the call, and after Eddings weighed in, Gonzalez was sent back to the batter's box. On Mock's next pitch, Gonzalez arched a ball barely beyond the outstretched glove of Nationals third baseman Ryan Zimmerman, who was running in the outfield grass, his back to the infield.

"When I got to second base, I asked the umpire," Gonzalez related, "and he said he could see the mark in the dirt."

That made it 1-0, and Colorado doubled its lead when Mock threw a wild pitch to the next hitter.

"I think the umpire made the right call," Mock said. "But regardless of whether he makes the right call or the wrong call, that's not for me to argue or get rattled about."

After Washington pulled within 2-1 on Adam Dunn's RBI double, the Rockies added to their lead with two runs off reliever Jason Bergmann in the eighth.

The Nationals finally got to Hammel in the fourth, loading the bases on two singles and a walk -- yet they came away with zero runs. That's because, with two outs, Elijah Dukes hit a sharp grounder that third baseman Ian Stewart made a nice diving stop to grab. Then, seated in the dirt, Stewart threw to second to force out Josh Willingham.

"We pitched like crazy," Tracy said, "and we defended -- especially at third base."

Game notes

Hammel retired the first 11 batters he faced; Mock started with 10 straight outs. ... Nationals LHP Sean Burnett made a nice play to get Gonzalez out on a bunt leading off the eighth, hopping off the mound and scooping an underhand toss while lunging head-first. ... Mock recorded eight of the season-high 13 strikeouts for Nationals pitchers.