Facing the San Diego Padres could help them make a push for first.
Colorado will try to remain undefeated against the Padres this season as these divisional rivals open a four-game series in Denver on Thursday night.
Led by three homers and six RBIs from Gonzalez and five hits, including two home runs, from Tulowitzki, the Rockies (32-28) pounded out a season-high 20 hits in Wednesday's 12-4 win at Cincinnati.
Colorado has won four of five to move one-half game ahead of San Francisco in the West and 2 1/2 behind Arizona, which finishes a series with St. Louis on Thursday before a weekend set with the Giants.
"Hopefully, we have some momentum, and it carries over," Todd Helton told the Rockies' website Wednesday after hitting one of the team's six homers - its most in five seasons.
Colorado will try to keep it going as it opens a 10-game homestand at Coors Field. The Padres (27-32), who were swept in Denver from April 5-7, also lost three at home to the Rockies the following week.
Colorado had a 38-17 scoring edge in those contests for its first six-game winning streak in this series.
Right-hander Jhoulys Chacin's first two wins of the season came against the Padres. He threw 6 2-3 innings of one-run ball in a 9-1 win April 7 then lasted five innings in a 9-5 victory six days later, giving up two runs.
However, Chacin (3-3, 4.26 ERA) is 0-3 with a 6.14 ERA in his last six outings and 0-2 with a 7.66 ERA in his last four in the Mile High City. He surrendered five runs in six innings of Saturday's 7-6, 10-inning home win against the Los Angeles Dodgers.
He'll face a San Diego team that defeated the Dodgers 6-2 on Wednesday to end a three-game skid.
The Padres continue their seven-game trip with Andrew Cashner (4-3, 3.65) making his first start at Coors Field. His only start against the Rockies was a 7-4 Padres loss Sept. 7, when he was charged for six runs and a career-worst 10 hits in 3 2-3 innings.
Cashner made a two-inning relief appearance against Colorado in a 6-3 loss April 6, getting tagged for a two-run homer by Michael Cuddyer, who's batting .421 during a nine-game hitting streak.
Cashner, 4-3 with a 3.61 ERA in eight starts since joining the rotation, allowed a career-high three homers in Thursday's 7-1 loss to Seattle.
"I've got to be better and not give up home runs," Cashner told the team's official website.
He has given up six homers in his last four starts after allowing one in his first four.
Dexter Fowler, the Rockies' leader with four homers against San Diego this season, was sick Wednesday - he did enter the game as an eighth-inning defensive replacement and struck out in his only at-bat - but he could return to the lineup.
Infielder Yonder Alonso, whose 29 RBIs lead San Diego, was placed on the 15-day disabled list prior to this game with a bruised right hand. The Padres activated outfielder Cameron Maybin, who was hitting .091 before going on the DL on April 17 with a right wrist injury.
Gonzalez and Tulowitzki have not homered against the Padres in 2013, but they're hitting a combined .400 with five doubles, nine runs and eight RBIs in the season series.