The Marlins were never able to overcome their early deficit, but Haren regrouped and made it through six innings. The 34-year-old kept his team within striking distance, but Miami eventually fell, 4-1, to Colorado at Marlins Park.
"They worked me hard from the first batter of the game. Blackmon hit a decent pitch," Haren said. "It was down, but kind of right in his wheelhouse. I had a couple of guys at two strikes, but I couldn't put them away."
The first inning unraveled fairly quickly.
"Arenado fought me pretty hard," Haren said. "I threw a split. That was the only split I threw all game, and he hit it 400 feet. But I was in a battle with him."
Tagged for three runs on two homers early, the day could have turned disastrous for Haren, but the veteran kept the score manageable.
"Obviously, after that, I settled in and gave the team a chance, which I was pretty proud of, because those games can get ugly," he said. "I know the Rockies have struggled to score runs, but the lineup is good. They've hit me well in the past."
Haren slammed the door after the first inning, finishing with three runs allowed on three hits while striking out five. It wasn't enough as he fell to 6-3 (3.22 ERA). It also was his first loss at Marlins Park this year, where he is now 3-1 with a 2.32 ERA.
"I tip my hat to Dan," Miami manager Dan Jennings said. "That's a true veteran right there. The first inning he wasn't on his game, but he stayed right with it, and he posted five shutout innings. We turned it over to the bullpen."
Haren threw 37 pitches in the first inning, but after that, he needed 65 to go the next five.
The Marlins were seeking a four-game sweep, but settled for a series win, with the Yankees up next on Monday to begin a home-and-home series.
"We face the Yankees. We can't be down," Haren said. "That's a really good ballclub. It should be a fun series, four games. We've got to come out tomorrow and play like the last few days, which has been much better."