DENVER -- All it took was one pitch to Wilin Rosario for the Arizona Diamondbacks to go from winning to losing.
Rosario hit a two-out, two-run homer in the bottom of the ninth inning, and the Colorado Rockies rallied to beat the Diamondbacks 7-6 on Thursday night. Rosario finished with four hits to lift the Rockies into a fourth-place tie with Arizona in the NL West.
Corey Dickerson led off the ninth with a single against Addison Reed (1-7). Two outs later Rosario, hit a towering drive an estimated 447 feet into the seats in left on the first pitch to give the Rockies their third straight win.
Rosario raised his arms triumphantly after the first walk-off home run of his career.
"I made a mistake and he definitely didn't miss it," Reed said.
Jordan Pacheco and Ender Inciarte each had two hits and two RBI for the Diamondbacks. Arizona came into the weekend series a game ahead of Colorado, which has been in the cellar since the All-Star break. The Rockies are trying to avoid a third straight last-place finish.
The Diamondbacks blew a five-run lead to deny starter Vidal Nuno his first win since coming to Arizona in a July 6 deal with the New York Yankees. Nuno allowed three runs on eight hits and struck out eight in 5 1/3 innings.
"I felt bad for Nuno. He pitched very good for us," Arizona manager Kirk Gibson said. "We couldn't hold him. And finally got walked off."
Colorado rookie Yohan Flande was pulled after five innings and failed to get his first win in his ninth major league start.
Arizona fell behind 1-0 on Michael Cuddyer's eighth home run leading off the second. Inciarte's two-run single in the third gave the Diamondbacks a 2-1 lead, and they scored four more in the sixth.
The Rockies made it close with two runs in the sixth and two more in the eighth. Josh Rutledge lined out to right with two on and two out to end the eighth before Rosario's heroics off Reed.
"A terrible slider. A hanging slider," Reed said. "Probably higher than belt high. It sucks that I gave up a walk-off home run. Part of the game. Bad pitch and paid for it."
LaTroy Hawkins (4-3) pitched a perfect top of the ninth.
Nuno has pitched well enough in 13 starts for the Diamondbacks to earn a win, it just hasn't happened. Before allowing six runs to San Diego on Sept. 12, he had gone five starts allowing two runs or fewer. Still, he hasn't been able to crack the win column in the NL.
Diamondbacks: RHP Daniel Hudson will be shut down for the rest of the season. He pitched an inning in relief against San Diego on Sept. 3 after missing more than 26 months due to two Tommy John surgeries. He had two more relief appearances and manager Kirk Gibson he had no setbacks. "Not because of an injury, just because he's come back from a long rehab process," Gibson said. "We were thinking four appearances (and) he got through three. Liked what we saw."
Diamondbacks: RHP Chase Anderson (9-6) will make his final start of the season. He held the Padres to two runs in five innings Saturday and has now logged a career-high 148 1/3 innings.
