De La Rosa, who earned his 73rd victory in a Colorado uniform, limited Miami to one run on four hits in seven innings, helping the Rockies salvage the series finale after they dropped the first three games.
"I'm really glad to win all those games for this team, and I hope we can win more," De La Rosa said. "I think I find my rhythm when I throw more strikes. I walked four guys today, but I still made my pitch when I needed, and I think that was the biggest key."
Dan Haren settled after allowing the two homers, and he went six innings, allowing three runs on three hits with five strikeouts. The right-hander is now 3-1 with a 2.32 ERA this season at Marlins Park.
Limited to just two runs in the first three games of the series, the Rockies broke through for three in the first inning. Before Haren could settle, he already was down a run after seven pitches, with Blackmon connecting on his eighth career leadoff shot. Blackmon previously hit a leadoff homer on May 3 in San Diego. The Rockies also capitalized on a one-out walk to Troy Tulowitzki, which set up Arenado's two-out, two-run homer to left.
"When you play with a lead, things tend to fall into place when you get starting pitching," Rockies manager Walt Weiss said.
Ichiro Suzuki's pinch-hit RBI single in the seventh was the lone run De La Rosa allowed.
"We won three of four games; I don't think we should really be hanging our heads after a tough loss like this," Haren said. "Against a good pitcher, good team, good lineup ... and go from there."
MOMENTS THAT MATTERED First-inning homers: When the Rockies scored three first-inning runs on the homers by Blackmon and Arenado, they gained not only their first lead of the four-game series, but their first advantage since Tuesday against St. Louis.
"As it turns out, Haren settled in pretty well, and those runs really made the difference in the game," Blackmon said. "So we kind of got him early before he got a good feel for everything, and it helped us win the game." More >
Return of Cishek: Former Marlins closer Steve Cishek made his first big league appearance since May 31. After spending nearly two weeks at Double-A Jacksonville, Cishek inherited a less-than-ideal situation in the seventh inning. The Rockies loaded the bases with one out vs. Vin Mazzaro, and Cishek was called upon to face DJ LeMahieu, who chopped a grounder to second. Miami nearly turned two, but LeMahieu was safe at first for an RBI fielder's choice. Cishek walked Tulowitzki, loading the bases, but he struck out Carlos Gonzalez.
"Glad to see Cishek come in, respond with the ground ball," Miami manager Dan Jennings said.
De La Rosa dances out of danger: After smooth sailing for most of the game, De La Rosa ran into trouble in the seventh inning. He allowed a two-out RBI single to Ichiro and Dee Gordon followed with an infield single. Ichiro stole third to put De La Rosa in a tough spot with Donovan Solano at the plate. But the veteran lefty responded and forced Solano into a groundout to escape the jam. More >
Haren hurt by homers: Without overpowering stuff, Haren knows he is going to give up home runs. That's been a constant all season, and it plagued him twice in the first inning. Blackmon led off the game with a blast to right, and Arenado tacked on a two-run shot to left in the same inning. For the season, Haren has allowed 13 home runs in 13 starts. His personal high is 31 (2006 and '10). Miami's franchise high is 37 by Livan Hernandez in 1998 in 234 1/3 innings. More >
"I was trying to not throw him [anything] right there. I know what kind of power that guy has and I just made my pitches, and I think we did a good job with him today." -- De La Rosa, on holding Giancarlo Stanton hitless in three at-bats against him
"[Haren] labored a little bit to get through that first inning. He didn't have the rhythm and tempo that he normally has. That being said, he limited the damage with only three runs and responded with five more innings. He put us in position to give us a chance to get back into that game and win it. Unfortunately, we were 1-for-10 with runners in scoring position. We didn't capitalize on four walks and four hits off their starter. We just didn't get it when we needed to with men in scoring position." -- Jennings
SOUND SMART WITH YOUR FRIENDS
Arenado made two errors on Sunday -- a throwing error in the first and fielding error in the third. It marked the first time in the Gold Glove winner's career that he recorded two errors in one game.
INJURY UPDATE Prado sprains right shoulder: The Marlins received a scare and some unfortunate news when third baseman Martin Prado suffered a right shoulder sprain after tumbling over first base in the first inning. The injury occurred after Prado reached on Arenado's throwing error. Prado's foot made contact with first baseman Ben Paulsen's glove. Miami listed Prado as day to day, and he's expected to miss at least the next two games. Solano filled in at third base. More >
WHAT'S NEXT Rockies: Colorado heads to Houston for a brief two-day stop. The Rockies will play two at Minute Maid Park -- the first coming on Monday at 6:10 p.m. MT -- before heading home to host the Astros for two games. Chad Bettis (2-1, 3.05 ERA) gets the start on Monday, looking for his fifth quality start in seven outings.
Marlins: The Marlins open a two-game home series with the Yankees at Marlins Park on Monday at 7:10 p.m. ET. Tom Koehler (4-4, 4.00) is a New York native who will get the nod for Miami. New York counters with Masahiro Tanaka (4-1, 2.48).
Joe Frisaro is a reporter for MLB.com. He writes a blog, called The Fish Pond. Follow him on Twitter @JoeFrisaro and listen to his podcast. Steve Wilaj is an associate reporter for MLB.com. This story was not subject to the approval of Major League Baseball or its clubs.