The Rockies evened their record at 3-3 on this pivotal 10-game homestand.
"We needed the win," manager Walt Weiss said. "I don't know if I'll go as far as say 'must-win.' We're still in July here, but we needed the win tonight."
Miami entered the series having not scored in 37 innings, but it is the Rockies who have struggled for runs in the first three games. They managed one Monday, two against All-Star Jose Fernandez on Tuesday and two more against Jacob Turner on Wednesday.
"Two runs here, hopefully you get more spark than that," Helton said.
The two runs didn't seem to be enough when the Marlins loaded the bases with no outs against reliever Edgmer Escalona in the seventh, but Colorado's bend-not-break bullpen came up big.
"We're just looking for contact," Marlins manager Mike Redmond said. "They're giving us a run. Anything but a strikeout, really, and we got two strikeouts."
"That's the whole game right there," Stanton said. "You execute there and we go into extras or we win that game. None of us did it. That's how you win games."
It helped make a winner of De La Rosa (10-5), who struggled early but turned in another strong outing to help the Rockies snap a two-game skid.
De La Rosa pitched out of trouble when Miami had runners on first and third in the first and second innings. After Turner singled in the second, De La Rosa set down 13 of his last 15, yielding only two-out singles to Hechavarria in the fifth and Placido Polanco in the sixth.
"My command wasn't so good in the first two innings," he said. "I was overthrowing a little bit in the first two, but after that I made quick outs."
De La Rosa was able to pitch in the sixth inning despite aggravating his sore left thumb on a sacrifice bunt in the bottom of the fifth. The thumb started bothering the left-hander in Toronto on June 17, but he hasn't missed a start. He said he will make his next start.
"I've been pitching with that for a while," he said.
De La Rosa allowed six hits and struck out four to reach double-digit victories for the first time since winning 16 games for the Rockies in 2009.
Turner (3-3) was a hard-luck loser for the second straight outing. He allowed two runs and six hits, struck out four and walked two in six innings. It was the third straight start he allowed just two runs.
Colorado went ahead in the second. Helton reached on a two-out double down the left-field line and scored on Nolan Arenado's single to left to make it 1-0.
"Probably made a couple too many mistakes, especially that second inning to Arenado," Turner said. "That slider was just a bad pitch."
Miami broke through in the eighth when Polanco scored on Donovan Solano's third single of the night. The Marlins threatened for more, but Matt Belisle struck out pinch hitter Justin Ruggiano with runners on first and second to end the inning.
"Ruge has had 12 homers and I felt right-on-right was a better matchup in the situation," Redmond said. "And I felt that was the time to break out and get a big hit."
Helton's double was the 579th of his career and moved him past Wade Boggs on the career list. ... Stanton is hitting .314 with seven home runs in 10 career games at Coors Field. ... Solano's three hits tied a career high. ... LeMahieu has hit safely in all five games he has played since the All-Star break. ... Colorado's Juan Nicasio (6-4) will face Nathan Eovaldi (2-1) in the final of the four-game series Thursday afternoon.