PITTSBURGH -- The last time Aramis Ramirez hit a home run in PNC Park wearing a Pittsburgh Pirates uniform, he was days from being traded away by a moribund franchise.

On Saturday he belted a three-run home run in the first inning, his first as a Pirate in Pittsburgh since July 20, 2003, and lifted the Pirates to a 4-3 win against the Colorado Rockies.

"It's fun to be in a pennant race," Ramirez said. "That's what you play for as a player, especially for myself being my last year. I've got something to play for every single day, it couldn't be better than that."

The third baseman was traded to the Chicago Cubs July 23, 2003 in a cost-cutting move that saw the Pirates lose their most promising young player. Pittsburgh brought him back nearly 12 years to the date of that trade to reinforce an infield thinned by injuries to shortstop Jordy Mercer and third baseman Josh Harrison.

Now that both have returned, Ramirez is a part of an infield that might push him and others to the bench some nights. But that's a good problem for the Pirates to have.

"We've got a lot of depth," Ramirez said. "We all want to play but when we're not, we're ready to come off the bench and that says a lot for us."

The Pirates moved to 30 games over .500 at 79-49 for the first time since they finished the 1992 season with a 96-66 record. Pittsburgh remained 3 1/2 games behind the St. Louis Cardinals in the race for the NL Central.

After an 18-22 start, the Pirates are 61-27 in their last 88 games but manager Clint Hurdle says the team doesn't think about its scorching pace.

"We've really programmed ourselves to be concerned about the game we're playing that day," Hurdle said. "We'll continue to do that with the goal in mind, the goal is to win the division."

Pirates left-hander J.A. Happ limited the Rockies to one run and five hits in 5 2/3 innings. He walked one and struck out two.

Happ (3-1) has won each of his last three starts and owns a 0.78 ERA over his last four outings.

"It was a battle all night long for sure," Happ said. "They fouled a lot of balls off."

Rockies left-hander Chris Rusin allowed three runs and five hits in six innings. Rusin (4-7) walked three and struck out five.

Ramirez's home run served as the only blemish against Rusin, who settled down to deliver a quality start after the New York Mets shelled him for 11 runs in two innings Aug. 22.

"I made one pretty big mistake which cost us pretty much the game," Rusin said. "I didn't get it as far in as I wanted."

The Pirates added an insurance run in the seventh at the expense of left-hander Jason Gurka, who only recorded one out after he relieved Rusin.

Second baseman Neil Walker and pinch hitter Michael Morse singled to start the inning and pinch runner Starling Marte scored on right fielder Gregory Polanco's fielder's choice.

Colorado drew within a run in the ninth against right-hander Mark Melancon. First baseman Ben Paulsen led off with a single and catcher Nick Hundley followed with a two-run home run.

Melancon prevented the Rockies from scoring again to pick up his 43rd save.

"Nick put a good swing on that ball," Colorado manager Walt Weiss said. "We grinded, made Melancon work."

Colorado broke through with a run in the third to draw within 3-1. Left fielder Brandon Barnes and Rusin singled leading off the inning and Barnes scored on center fielder Charlie Blackmon's fielder's choice.

Blackmon stole second and took third on a throwing error but was stranded when shortstop Jose Reyes flew out and right fielder Carlos Gonzalez popped out.

NOTES: Pittsburgh paid tribute to its 1960 World Series team with a pregame ceremony featuring 10 members celebrating the 55th anniversary of the franchise's third of five titles. ... Pittsburgh LF Starling Marte was out of the starting lineup with a day off after he played in each of the Pirates' last 28 games. Marte pinch ran in the seventh inning and remained in the game in left field. ... Colorado 1B Ben Paulsen was back in the starting lineup after he did not play Friday. Paulsen is batting just .176 (3-for-17) in his last week of play and .244 during the month.