The victory rewarded heretofore hard-luck righty Jason Hammel (9-8), who went seven innings for his first win since Aug. 20, even though he's pitched well in the majority of his outings.
More importantly, winning put the Rockies 3 1/2 games ahead of their nearest Wild Card competitor, the Giants, who absorbed a 12-1 beating at the hands of the Dodgers. The Rockies also are four games up on the Marlins and 4 1/2 better than the Braves.
As well as Hammel pitched -- he didn't give up a hit after Justin Upton's three-run homer in the third, and held the D-backs to four hits overall -- he needed the Rockies' late surge.
The Rockies finally benefited in the ninth, courtesy of Spilborghs' double and Jason Giambi's pinch-hit, three-run shot, his first homer since joining the Rockies on Sept. 1.
While going 3-5 thus far on a road trip that ends with Sunday's finale with the D-backs, the Rockies have exceeded four runs in a game just twice. The only time before Saturday was Friday night's 7-5 loss to the D-backs.
"With the way things have been going offensively, as frequently as it has of late, you ask yourself the question, 'Is this going to come back to haunt us?'" Tracy said. "Tonight, we followed it up with a terrific ninth inning and did put it away."
Carlos Gonzalez and Troy Tulowitzki homered in the first off Max Scherzer (9-10). It was Gonzalez's 12th homer of the year. Tulowitzki, who has 29 homers in what's becoming a season comparable to the best all-time by an NL shortstop, has homered in a career-high four straight games. But the Rockies needed a two-run fourth to retake the lead, 4-3.
It took until the seventh for the Rockies to add to the advantage. But Hammel made sure it didn't become a disadvantage. Not having full command of his fastball, Hammel used mainly his curve to keep the D-backs off the bases.
"I made a bad pitch [to Upton] and paid for it," Hammel said. "My mind-set after that was, 'That's all they get.'"
Spilborghs pinch-hit for Brad Hawpe with two on in the seventh and doubled off Clay Zavada for a 5-3 advantage, but the inning ended with no further scoring when Ian Stewart fanned with the bases loaded. The lead became tenuous again when Stephen Drew tripled and scored on Upton's sacrifice fly against Rafael Betancourt in the eighth.
"I thought we had some decent momentum after the eighth and they just simply took us out of the game in the ninth," D-backs manager A.J. Hinch said.
Spilborghs' ninth-inning double came off Esmerling Vazquez. Giambi homered off Scott Shoeneweis.
The ninth inning showed the potential of the Rockies' order. By then, Spilborghs, who has been a starter at times, and Dexter Fowler, who started much of the year in center field before a bruised right knee cost him 14 recent games, were in the game. And Tracy could go to Giambi, who is 4-for-11 with nine RBIs and seven walks for the Rockies.
The recent hitting issues have been dissected frequently, but that's because the team is full of offensive producers.
"I can't imagine a team that has so many guys with 40-plus RBIs [nine]," said Spilborghs, who has 48. "We don't have one guy with 100 RBIs. But that proves that our team has a lot of players who have contributed more than just a utility guy."