PITTSBURGH — The Pittsburgh Pirates didn't panic when they fell behind early to the Colorado Rockies for the second straight game.

"This team never gives up," Luis Rivas said. "We're going to work hard the whole way."

The second baseman had three hits, three RBI and finished a home run short of the cycle, as the Pirates rallied again to beat the Rockies 6-4 Tuesday night.

Pittsburgh, which fell behind 3-0 to Colorado Monday before winning 8-4, came back from a 4-0 deficit in the third inning.

Rivas, starting in place of injured second baseman Freddy Sanchez, lead the rally. He had an RBI single in the third and added a two-run triple in the fifth against Colorado starter Glendon Rusch.

"When Luis is called upon to start, he has had some big games," Pittsburgh manager John Russell said. "He did a great job tonight."

Rivas, who also doubled in the first, came to bat in the seventh with a chance for the cycle. He hit into a force out and later scored, but admitted he was thinking about the feat.

"A little bit," he said. "I was just trying to put the ball in play and whatever happened, happened."

Down 4-3, the Pirates went ahead by scoring two runs against reliever Matt Herges (3-4) in the sixth. An error by Rockies center fielder Willy Taveras led to a run, and Chris Gomez hit a sacrifice fly to bring home Doug Mientkiewicz with the go-ahead run.

Jason Bay, who had two hits, added an RBI in the seventh for the final margin.

Nate McLouth had two hits and scored two runs for Pittsburgh. One night after hitting a mammoth home run into the Allegheny River, the outfielder made an outstanding defensive play in the third, leaping at the warning track to catch a fly ball hit by Garrett Atkins.

McLouth is making a case for his first Gold Glove. He hasn't committed an error this season.

"He's done a great job," Russell said. "He's worked awfully hard."

Colorado manager Clint Hurdle was impressed by McLouth, whom he managed in the All-Star Game.

"McLouth's a player," he said. "He plays big. That catch he made tonight, there's not many players in the game that make that catch. He hit a ball in the river (Monday) night. He Mickey Mantled us."

Jason Davis (1-0), making his first appearance since being called up from Triple-A Indianapolis on Sunday, pitched a scoreless sixth inning and Tyler Yates earned his first save of the season.

Pittsburgh closer Matt Capps is currently on the disabled list with bursitis in his right shoulder, and Yates said he would happy to fill the ninth-inning role. He retired the side Tuesday night.

"The ninth inning is the hardest to pitch for a reliever," said Yates, who has four career saves. "It gets me pumped up."

Pittsburgh starter Yoslan Herrera allowed four runs on six hits and four walks in five-plus innings and struck out one. He got his first major-league hit when he singled and later scored in the fifth.