Todd Helton hit a tiebreaking sacrifice fly in the sixth inning and the Colorado Rockies cooled off Stephen Strasburg with a 4-2 victory over the Washington Nationals on Monday night.

Jeff Francis pitched five effective innings as the Rockies won for just the fourth time in 18 games. Dexter Fowler had two hits and Carlos Gonzalez delivered a tying RBI single.

Strasburg (9-2) allowed three runs and six hits in six innings. He was bidding to become the first Washington-based pitcher to win seven straight starts since Bob Porterfield did it in his final seven starts for the Senators in 1953. The last pitcher from the Nationals franchise to win seven straight starts was Pedro Martinez in 1997 for the Montreal Expos, who moved to Washington.

Strasburg helped himself with a tiebreaking RBI double in the fifth, putting the Nationals ahead 2-1. He also had a sacrifice in the third that set up Ryan Zimmerman's run-scoring double.

But the Rockies went ahead for good in the sixth. Fowler led off with a triple into the right-field corner. Strasburg then beaned Marco Scutaro with his first pitch, a 95 mph fastball that audibly resounded off Scutaro's helmet. He got up quickly but was replaced by Chris Nelson after being examined by Rockies trainer Keith Dugger.

Gonzalez followed with a run-scoring single, and Michael Cuddyer's base hit loaded the bases. Helton then drove in Nelson with a fly ball to center field.

After falling behind Jordan Pacheco 3-0, Strasburgh intentionally walked him to load the bases for Wilin Rosario and struck him out on an 82 mph curveball. Jonathan Herrera then grounded to shortstop Ian Desmond, who ran to second for the forceout.

The Rockies tacked on a run in the seventh when pinch-hitter Eric Young led off with a walk, stole second and scored on Nelson's one-out single.

Strasburg struck out eight and walked one. He had not allowed more than two runs in each of his past four starts.

Nationals rookie Bryce Harper went 0 for 4 with three strikeouts.

Josh Roenicke (3-0) followed Francis with two scoreless innings. Matt Belisle worked the eighth and Rafael Betancourt finished for his 12th save.

Betancourt allowed consecutive one-out singles, bringing up pinch-hitter Roger Bernadina. He hit a hard liner to right field but just a few steps from Cuddyer. Betancourt then got Danny Espinosa to bounce out to second to end the game.

Jesus Flores had three hits and scored twice for Washington.

NOTES: The temperature of 100 degrees was the warmest ever for the start of a game at Coors Field, where the Rockies played their 1,406th regular-season contest. ... Rockies RHP Juan Nicasio (left knee strain) will face hitters in a simulated game Tuesday. He last pitched for the Rockies on June 2. ... The Rockies optioned struggling starter Alex White to Triple-A Colorado Springs and recalled reliever Zach Putnam. ... The Nationals placed outfielder Xavier Nady (right wrist soreness) on the 15-day disabled list retroactive to Sunday and activated infielder-outfielder Mark DeRosa, who had been on the disabled list for 50 games with a left oblique strain. ... The Nationals released reliever Brad Lidge, who was designated for assignment June 17. ... Christian Friedrich (4-4) will start Tuesday for the Rockies against Gio Gonzalez (9-3).