Wilfredo Lee, Associated Press
Colorado Rockies' Juan Nicasio pitches during the first inning of a baseball game against the Miami Marlins, Tuesday, May 22, 2012, in Miami.

MIAMI — Colorado Rockies manager Jim Tracy has the owner's support. What he lacks is pitching.

The Rockies blew a big early lead for the second night in a row, and their losing streak reached six games Tuesday with a 7-6 defeat against the Miami Marlins.

The Rockies (15-27) are off to their worst start since 1995, but owner Dick Monfort told the Denver Post he will not fire Tracy or general manager Dan O'Dowd.

"It means a lot to me," Tracy said.

Monfort said he doesn't believe Tracy has lost the team, and said the Rockies are playing hard. Tracy agreed.

"The effort that's been given, I think my message is being heard loud and clear," Tracy said. "It's extremely frustrating for all of us. To sit here and know the kind of effort they're putting forward and getting frustrated, it's painful."

Trailing 7-4 in the eighth, the Rockies kept battling. They scored twice in the inning, but left fielder Chris Coghlan preserved the Marlins' one-run lead when he made a running, leaping catch to rob Marco Scutaro of a hit, ending the threat and stranding a man at third.

Heath Bell gave up a leadoff double in the ninth, then retired Carlos Gonzalez, Troy Tulowitzki and Todd Helton for his seventh save in 11 chances.

On Monday, Miami trailed 4-0 in the first inning and won 6-4. A succession of bloopers and bleeders helped Colorado score three runs in the first against Ricky Nolasco, but Juan Nicasio (2-2) couldn't hold the lead.

"I think where we messed up once again was early in the game with the starting pitching," Tracy said. "We've played two games in this series, and we've score seven runs in the top first inning, and let them right back in within a few hitters."

The Colorado pitching staff came into the game last in the NL in ERA, hits, home runs and wild pitches. Nicasio gave up six runs, five earned, in five innings and remained winless in his past four starts.

"I don't know why I felt down in the first few innings," he said. "I did not do my job."

Errors by shortstop Tulowitzki and catcher Wilin Rosario led to a pair of unearned runs.

Nolasco (5-2) pitched six innings and became the Marlins' sole leader in career wins, improving his record to 69-53.

"I'm glad we were able to bend but not break," Nolasco said. "A lot of guys said congratulations. I appreciate that. Thanks to the Marlins organization for giving me the opportunity to be here this long."

Nolasco had been tied with Dontrelle Willis for the most victories.

"A lot of great pitchers went through this organization," manager Ozzie Guillen said. "He should be proud."

Nolasco broke a tie in the third with a two-run double that put Miami ahead to stay.

The Marlins (24-19) tied the franchise record for victories in May. Their 16-5 record this month is the best in the majors, and they're five games above .500 for the first time this season.

"We're starting to swing the bats more," Nolasco said. "It's a lot easier to pitch when you have confidence your hitters are going to give you some runs. Everything is kind of clicking for us now."

Miami doesn't have pennant fever yet, however. The crowd of 22,242 was the smallest so far at the city's new ballpark.

Michael Cuddyer went 3 for 3 with a walk for the Rockies, and Rosario drove in two runs. But Colorado went only 4 for 18 with runners in scoring position.

NOTES: Rockies 2B Jonathan Herrera departed in the sixth inning with a tight right hamstring and might go on the disabled list, Tracy said. ... Marlins LF Austin Kearns left the game in the fourth with a tight right hamstring. His status is day to day. ... 2B Omar Infante rejoined the Marlins after flying to Venezuela for a family funeral, but he was held out of the lineup. ... Right-handed hitters are batting only .150 this year against winless RHP Alex White, scheduled to start Wednesday for the Rockies. Left-handed hitters are batting .326.