PITTSBURGH -- Craig Monroe came out of the dugout for a curtain call following his second home run of the game.
For the nine-year veteran, it was his official welcome to Pittsburgh.
"That was awesome," he said. "To be with a new team and to get that appreciation from the crowd. It was spectacular."
Monroe, making his second start of the season, homered off Atlanta starter Jo-Jo Reyes (0-1) with two outs in the sixth inning. He again went deep off reliever Buddy Carlyle with two outs in the seventh.
It was the fourth multihomer game of the right fielder's career and the third time he had six RBIs.
"Obviously, it was a great day for him," Pittsburgh manager John Russell said. "He's capable of that. He can drive the ball for us."
The 32-year-old signed with the Pirates in January after hitting .202 with eight home runs and 29 RBIs in 163 at-bats for Minnesota last season. He earned a spot on the Pirates' bench after leading the team with eight home runs and 16 RBIs in spring training.
Monroe had been 1-for-8 this season before Saturday's performance.
"That was fun," he said. "To be able to come off the spring training I had and continue to be able to help the team. It feels good. I look forward to staying productive."
Jesse Chavez worked a perfect ninth to complete the four-hitter.
Pittsburgh, which blanked Atlanta for the second consecutive game, has three shutouts in its past five games.
The Pirates, under first-year pitching coach Joe Kerrigan, entered Saturday's game with a major league-best 2.90 ERA. Though its still early, it's a dramatic improvement from 2008, when the Pittsburgh pitching staff was the worst in the National League with over five earned runs allowed per game.
"I knew we would be better," Russell said. "Last year, we were not good at all. With Joe, there's now a sense of urgency to go out there and compete."
Snell said the team's starting staff has been feeding off each other's early success.
"It's fun right now," he said. "All of us are in a competition with each other. I'm sure the hitters are doing the same thing."
Reyes, called up before the game to start in place of Tom Glavine, allowed five runs and seven hits in 5 2/3 innings.
The left-hander has lost eight straight decisions dating back to last season. That's the longest losing streak by an Atlanta pitcher since Marty Clary dropped nine in a row in 1990.
Leading 1-0, the Pirates broke the game open by scoring four runs in the sixth against Reyes.
Sanchez tripled with one out and scored on McLouth's single to make it 2-0.
After McLouth stole second base, Doumit was intentionally walked and Adam LaRoche struck out. Monroe followed with his first homer of the season to make it 5-0.
Andy LaRoche doubled and Ramon Vazquez was intentionally walked before Reyes was lifted for Carlyle.
"I felt good out there today," Reyes said. "It's just that the screws came off in the sixth inning. I made one bad pitch all game, and it hurt. But I'm not dwelling on it because the first five innings are what I wanted to do."
The Pirates added four more runs in the seventh against Carlyle. Doumit had an RBI double and Adam LaRoche was intentionally walked before Monroe again homered.
Omar Infante had two hits for Atlanta, which has lost five straight.
Atlanta's offensive struggles have come without third baseman Chipper Jones and shortstop Yunel Escobar in the lineup. Jones was out for the fourth consecutive game with a bruised left thumb, and Escobar missed his second straight game with a strained abdominal muscle.
Braves manager Bobby Cox said both players could return for Sunday's game against Pittsburgh.
"We haven't had our whole team in the lineup yet," Cox said. "It would be great to get everybody back."
Pittsburgh's back-to-back shutouts were its first since blanking Arizona and Philadelphia on Aug. 6 and 8 last season. ... Pirates SS Jack Wilson was out of the starting lineup for the third time in four games because of a bruised left middle finger. ... The Pirates played their first Saturday afternoon game at PNC Park since September 3, 2005. ... Monroe's six RBIs are the most by a Pirates player since Jose Castillo had six against Milwaukee on May 30, 2006. ... Atlanta is 5-6 after starting the season 5-1. The Braves are 0-2 on a nine-game, 10-day road trip.