DENVER -- The Colorado Rockies resolved one of their biggest concerns by finally winning a close game. They might have something new to worry about, though.
The victory denied the Marlins' bid for a series sweep and marked the Rockies' first win this season in a one-run game after losing their first eight.
On the down side, manager Clint Hurdle said after the game that Tulowitzki "tweaked" his left quadriceps trying to field an errant throw to second in the sixth inning by Cook. Tulowitzki, replaced in the ninth inning by Clint Barmes, said he doesn't think the injury is serious -- but he missed 46 games last season when he tore the quadriceps tendon in the same leg.
"We'll see how it feels [Monday]," said Tulowitzki, adding that he planned to come in on the team's off day for additional treatment. "Then I'll come back on Tuesday and hopefully I'm ready to go."
Hurdle said Tulowitzki, whose home run produced his seventh RBI in seven games after getting none in his previous 17, probably could have played through Sunday's game but was replaced in the final inning as a precaution.
"If something crazy happened, he's got to go make a play and that thing is really injured and he's out a substantial amount of time, the way he's starting to heat up at the plate, it just wasn't in our best interest," Hurdle said.
Tulowitzki's health took some of the edge off the Rockies' long-awaited close victory, but the win was welcomed by the struggling Rockies nonetheless.
"For us to go out there and win a one-run game was huge," Cook said. "It helps our confidence tremendously."
The team's No. 1 starter, Cook (2-1) allowed two runs -- one earned -- and four hits in helping the Rockies snap a three-game skid. He also picked off a runner at second base to get out of a fourth-inning jam and buckled down to get out of another in the sixth after fielding a grounder and throwing wide of Tulowitzki.
"We had people on base everywhere," Florida manager Fredi Gonzalez said. "We just couldn't get the big hit. Cook had something to do with it. He made the pitches when he needed to."
Huston Street, the last of three Colorado relievers, got three outs for his fourth save in four chances.
The Marlins pulled to within one in the sixth inning. Emilio Bonifacio doubled off Cook to start the inning and Hanley Ramirez singled him home one out later. Ross Gload reached on a fielder's choice and Ramirez went to third on Cook's throwing error before Ramirez scored on Dan Uggla's RBI grounder.
Colorado, taking a lead for the first time in the series, got a solo homer from Tulowitzki in the first inning off Chris Volstad (2-2), who allowed three runs, two earned, in six innings.
"I needed to bear down and get out of those tough innings," Volstad said. "I got stronger in the later innings. I finally started to get the ball down and got more ground balls. I need to get out of that first inning. That has given me trouble my last couple of starts."
The Rockies went up 3-0 when Helton doubled in the fifth to score Cook, who reached on third baseman Bonifacio's throwing error.
The Marlins optioned struggling outfielder Cameron Maybin to Triple-A New Orleans. Maybin was batting .202 in 26 games. He also was caught in a ninth-inning run-down Sunday after being sent in to pinch-run for John Baker, who had doubled with one out. ... Ramirez has at least one hit in each of his 13 career games at Coors Field. ... Utilityman Omar Quintanilla made his first start of the season for Colorado. His assignment at second base marked the Rockies' 27th different lineup in 30 games. ... Wanting to get rookie Chris Coghlan's bat in the lineup, Florida started the infielder in left field. He handled four putouts with no problem despite not playing regularly in the outfield since he was the 12-year-old center fielder for the AAU Tampa Renegades. His left-field counterpart, Seth Smith, made a leaping grab at the wall of Coghlan's drive in the eighth. ... Colorado's Garrett Atkins is hitless in his last 15 at-bats.