De La Rosa (13-6), who won his third straight start, entered 0-3 with a 7.71 ERA, and had given up four home runs and 19 hits in 16 1/3 innings in Philadelphia.
But this time, he held the Phillies to three runs, two earned, on three hits and three walks with three strikeouts. His only troublesome inning was the third, when first baseman Todd Helton's fielding error -- on his 40th birthday -- was part of a three-run inning. But he struck out Michael Young to end the inning and start a stretch of 11 straight retired batters.
"I finally won one game here, and I finally won a game against those guys," said De La Rosa, who was 0-4 in seven appearances against the Phillies. "They're a tough team for me."
Troy Tulowitzki homered for the 22nd time this season and second time in as many games, this one for two runs in the first inning. Wilin Rosario ran his hitting streak to a career-best 11 with his 18th homer, a solo shot in the third.
The Rockies (59-68) split the first two of a four-game series at Citizens Bank Park. By improving to 2-3 on this 10-game trip, they've already done better than their last road trip, when they went 1-9. They're still looking for their first road series win since July 8-10 at San Diego, and one more win would give them their first road series split since July 11-14 against the Dodgers.
De La Rosa was the biggest reason.
Since mid June, De La Rosa has been bothered by a bruise on his left thumb, and he admitted the thumb went numb on a broken-bat grounder to the mound in the second inning. However, his fastball had more life than in any of his recent starts, and his changeup and slider were sharp.
"That was real good -- everything was working and we were right together, on the same page," Rosario, the catcher, said.
Tulowitzki, whose homer in Monday night's 5-4 loss was his first since Aug. 2, homered off Tyler Cloyd (2-3) with one out in the first. Michael Cuddyer then doubled and scored on a wild pitch to make it 2-0.
Tulowitzki had a National League-leading .347 batting average before June 13, when he suffered a broken rib that cost him 25 games. From his July 11 return through Aug. 12, he hit .205 with four homers and saw his season average dip to .306. But he has hit safely in seven games since then, going 11-for-27 (.407) with five RBIs.
"He looks like he's on time up there again," Rockies manager Walt Weiss said. "He was searching for it for a bit."
Dexter Fowler's RBI single made it 4-0, and Rosario made it 5-0 in the third, homering to center on the first pitch of his at-bat.
"Just trying to do too much, trying to be too fine," Cloyd said of his early struggles. "Mechanics wore down a little bit. Later on, obviously I settled down and started trusting that my stuff was going to go where I wanted it to go."
Helton mishandled a Carlos Ruiz grounder with two on and one out in the third. Chase Utley added an RBI single and a Dominic Brown sacrifice fly cut the difference to 5-3.
Corey Asche's infield single with one out in the Phillies' seventh and a walk to John Mayberry led to De La Rosa's exit. Kevin Frandsen flied to center against Matt Belisle, then Helton atoned for the error and ended the threat with sleight-of-hand.
Jimmy Rollins, facing Rex Brothers, grounded to Nolan Arenado who was headed toward the line but made a strong leaping, twisting, one-hop throw. Helton had to leave the bag to glove the ball, and television replays showed he never tagged Rollins. But first-base umpire Jim Wolf called the out, and Rollins didn't protest. Neither did Phillies interim manager Ryne Sandberg.
"That was the biggest thing, Jimmy had no argument," Sandberg said. "He told me later he felt something over there on his back. From my angle, I just saw a throw that was slightly up the line with a swipe tag."
Helton finished the play with a matador's flourish.
"I don't know if you'd call it selling it -- it's just my natural reaction to think I tagged him, even though it didn't work out that way," Helton said. "It worked out great."
What happened at the back end aside, it was yet another highlight defensive play from Arenado, who has earned legitimate consideration for a Gold Glove Award even though he is a rookie.
"Right when I got it, I knew he could run," Arenado said. "Once I was able to get a grip, I just chucked it. Luckily it was somewhere near. It could've gone down the line. It could have been in right field."
Brothers overcame a one-out walk to Utley and two balks to throw a scoreless eighth. Brothers said he was warned once early in the year about not coming set completely, and didn't dispute the balk calls.
Rafael Betancourt earned his 16th save in 17 chances with a perfect ninth. It was Betancourt's first save since July 14, before he missed four-plus weeks after an emergency appendectomy. The relievers pitched 2 2/3 hitless innings with one walk.