Updated

Todd Helton's sacrifice fly in the sixth inning proved to be the difference as the Colorado Rockies downed the Washington Nationals, 4-2, in the opener of a four-game set.

Dexter Fowler added two hits, an RBI and a run scored, while Rafael Betancourt left the tying runs on base in the ninth to earn his 12th save of the year for Colorado, which won for the third time in five games.

Josh Roenicke (3-0) received the win with two innings of scoreless relief in place of starter Jeff Francis, who allowed two runs on five hits over five innings.

"It was a really good ball game and we pitched," Colorado manager Jim Tracy said. "We pitched all the way through."

Stephen Strasburg (9-2) gave up three runs on six hits and a walk with eight strikeouts in six full frames to suffer his first road loss of the season. He had been 5-0 through seven road starts entering Monday's game.

"I went out there and pounded the strike zone," Strasburg said. "It seemed they were just hitting it right beyond our gloves, basically."

Strasburg also had a run-scoring double as the Nationals lost for the third time in four tries.

Betancourt entered for the ninth and fanned Ian Desmond to start the frame before back-to-back singles by Tyler Moore and Jesus Flores placed the tying runs on the bases.

But Betancourt retired pinch-hitter Roger Bernadina on a hard liner to right before Danny Espinosa hit a slow bouncer to second to end the game.

Washington struck first in the third inning when Flores led off with a single, advanced to second on Strasburg's sacrifice bunt and crossed the plate on Ryan Zimmerman's two-out double down the first-base line.

But the Rockies quickly knotted the game in the bottom of the frame after Wilin Rosario hit a leadoff double and later came home on Fowler's two-out, infield single.

The Nationals, though, regained the lead in the fifth on back-to-back doubles by Flores and Strasburg.

After Washington squandered Desmond's two-out triple in the top of the sixth inning, Colorado was able to go on top for good in the home sixth.

Fowler opened the inning with a triple into the right-field corner and after Marco Scutaro was hit in the head with a pitch that knocked him out of the game, Carlos Gonzalez singled to right to score Fowler.

Michael Cuddyer followed with a base hit to load the bases before Helton lifted a sacrifice fly to center field, plating pinch-runner Chris Nelson, who replaced Scutaro.

Jordan Pacheco was then intentionally walked to fill the bags again, but Strasburg fanned Rosario and induced an inning-ending grounder to short by Jonathan Herrera to keep it a 3-2 game.

Eric Young worked a pinch-hit walk off Tom Gorzelanny, stole second and came home on Nelson's single to right in the seventh to give Colorado a two-run advantage.

Game Notes

With a game-time temperature of 100 degrees, it was the hottest home game in Rockies history...Francis struck out five and did not issue a walk...Strasburg had his six-start win streak snapped...The Rockies have won eight of their last 11 games against Washington.