Todd Helton hit a pair of three-run homers as the Colorado Rockies cruised past the Cincinnati Reds, 9-6, in the opener of a three-game set at Coors Field.
Charlie Culberson added a two-run double and Wilin Rosario had four hits and scored a pair of runs for the Rockies, winners in five of their last seven games.
Jorge De La Rosa (15-6) gave up three runs on eight hits over six innings to pick up his fifth straight win.
Ryan Ludwick hit a solo homer and Ryan Hanigan had two hits and two RBI for the Reds, who hold a six game lead over the Arizona Diamondbacks for the final spot in the NL Wild Card.
Bronson Arroyo (13-10) gave up six runs on nine hits over 3 1/3 innings to absorb the loss.
"When it happens for him it happens quickly," said Cincinnati manager Dusty Baker about Arroyo's tough outing. "You can't even get anyone warm fast enough."
DJ LeMahieu doubled home Corey Dickerson in the first inning to give the Rockies an early lead, but Hanigan's RBI single in the second scored Todd Frazier to tie things up.
Hanigan singled home Frazier once again in the fourth inning to put the Reds on top 2-1, but Helton belted his first three-run blast in the home half to give Colorado a 4-2 edge.
Troy Tulowitzki and Rosario opened the frame with back-to-back singles before Helton smoked an Arroyo change-up over the right-field wall. Culberson added a two-run double later in the frame to give the Rockies a four-run edge.
Ludwick's homer in the fifth pulled Cincinnati within 6-3.
The Rockies broke the game open in the seventh with Helton's second three-run round-tripper, a laser that just cleared the wall in right field.
"He's one of those guys that's going to be able to hit when he's 52," said Colorado manager Walt Weiss about Helton. "That was a great night for Todd and for everybody that was here."
The Reds made things interesting in the ninth. Chris Heisey singled and Shin- Soo Choo doubled to open the frame. Brandon Phillips followed with a two-run single up the middle. After Joey Votto grounded out, Devin Mesoraco lifted a sacrifice fly to center to plate Phillips, but Jeff Francis got Jay Bruce to ground out to end the game.
The last time Helton had two home runs in a game was April 26, 2011 ... Tulowitzki went 3-for-4 with two runs scored ... The Rockies had 19 total hits ... Colorado was 4-for-11 with runners in scoring position ... The Reds went 3-for-14 with RISP ... Arroyo had a four-start winning streak snapped.