SCOTTSDALE, Ariz. -- Salt River Fields looked like a pitchers' paradise as the Rockies' and Cubs' No. 2 starters dueled Tuesday. Colorado's Jorge De La Rosa edged Carlos Zambrano in the early innings, and the Rockies held a one-run lead through the first six innings until Jordan Pacheco hit a three-run homer in the bottom of the seventh to break open the game en route to a 4-0 win for Colorado.

De La Rosa threw four innings in this second Cactus League start, holding the Cubs to two hits while striking out five and getting five ground-ball outs. His breaking balls were much sharper than his first time out, and he went to his slider with greater frequency, putting a lot of sink on his pitches and keeping the Cubs off balance.

"I felt much better than the first time," De La Rosa said. "Today I kept the ball down. That's why they hit a lot of ground balls. That was the important thing today. My command was much better, and all my breaking balls were sharp. That didn't happen the last game."

Zambrano did well in his three innings on the hill, yielding one run on five hits while striking out one. He let up four of the five hits in the second inning, but was able to escape the jam with minimal damage.

In his last start, Zambrano complained of a little arm fatigue. That wasn't an issue on Tuesday. He was much crisper with his pitches. In the Rockies' third, Zambrano had Carlos Gonzalez spinning and falling onto the dirt as he tried to deal with a third strike.

"Good hitter, good pitches," Zambrano said. "He hit .336 last year. It's the same with [Troy Tulowitzki]. He's a good hitter, so good pitches to them. Sometimes we make a mistake with some [bad] hitters, but obviously there are no [bad] hitters. They are very good hitters. Not only them, but any good hitters, I have my best stuff [for] them."

Todd Helton led off the Rockies' second with a single to left and was thrown out trying to advance to second on a wild pitch. Jose Lopez singled to center, and after catcher Matt Pagnozzi moved him to second on a grounder to third, Thomas Field plated him with a single up the middle. De La Rosa added a base knock to left before the Rockies were retired. Helton singled again in the fourth.

The Cubs got one extra-base hit, a ground-rule double from Geovany Soto to lead off the second, but De La Rosa stranded him at second with three groundouts. Starlin Castro led off the fourth with a single up the middle, and they opened the fifth with Kosuke Fukudome drawing a walk and Blake DeWitt singling him to third. But Rockies reliever Clayton Mortensen struck out two and finished the inning with a fielder's-choice groundout to preserve the shutout.

Rockies Up Next: Jhoulys Chacin makes his third start of the season since being penciled in as the No. 3 starter, when the Rockies take on the Angels at 1:05 p.m. MT on Wednesday, live on Gameday Audio. Chacin has relished the chance to have a more relaxing Spring Training without focusing on making the club. He is focused on his fastball command, but is also working on his curveball and hopes to pair it with his sinking changeup as effective alternatives to the slider he has relied heavily on in the past. Chacin will be followed by Huston Street, John Maine, Christian Friedrich, Rex Brothers and Cory Riordan.

Cubs Up Next: Matt Garza will make his second Cactus League start and third appearance on Wednesday when the Cubs play host to the Royals at HoHoKam Park in Mesa, in a free, exclusive cubs.com webcast at 2:05 p.m. CT. It's a rematch of last Friday, when Garza also faced the Royals. In that game, he was hit in the lower right side of his back by a line drive, but finished the inning. Because the Royals are starting a lefty, Jeff Baker will lead off. Baker batted .350 against lefties last season, .106 against right-handers.