Tulowitzki's second solo blast of the day came immediately after Drew Stubbs belted a two-run shot off Joaquin Benoit (3-1) that snapped a 3-3 tie in the eighth inning. Charlie Blackmon went deep earlier for Colorado and finished 2- for-4 with a pair of runs scored.
The power surge, along with 4 1/3 scoreless innings of work from four Rockies relievers, enabled Colorado to earn back-to-back wins for the first time since a season-high five-game streak from June 11-15.
San Diego put up a pair of solo homers in defeat, including the first of Jake Goebbert's major league career. Seth Smith had the other as part of a 2-for-3 performance.