PITTSBURGH -- The latest addition by the suddenly splurging Pittsburgh Pirates hustled into the dugout in the sixth inning on Saturday night eager to step into the batters box against St. Orlando Scandrick Jersey . Louis if necessary. Take a breath, Justin Morneau. The Pirates -- and the pennant race -- arent going anywhere. A.J. Burnett scattered four hits over seven innings, Russell Martin hit a three-run homer and the Pirates beat the Cardinals 7-1 on Saturday night to regain sole possession of the NL Central lead. Neil Walker added three hits for the Pirates, who improved to 79-56 and moved within three victories of their first winning season since 1992. And theres still a month left. "Its a great feat," Burnett said. "Its been a long time, but our goals have been higher than that." Burnett (7-9) gave up one run while striking out six and walking one. He received plenty of help only hours after the Pirates acquired Morneau from the Minnesota Twins, hoping the 2006 AL MVP can give a middling offence a jolt heading into the stretch drive. Morneau didnt waste time getting to Pittsburgh. He left Texas -- where the Twins were playing the Rangers -- in the middle of the afternoon, arrived at the airport just before 8 p.m. and was in uniform trading jokes with his new teammates moments after pulling on a black-and-gold jersey. "You try to get here as quick as you can because you want to be a part of this," Morneau said. The 32-year-old first baseman will have to wait until Sunday to get his first major league at-bat for someone other than Minnesota. By the time he was inside PNC Park, the Pirates had things well in hand. Martin keyed a five-run second with his drive off Lance Lynn (13-9), who has a 7.66 ERA in his last four starts. "It just (ticks) you off and thats where Im at," Lynn said. "Im not happy with the way Im throwing the ball, but Im going to fix it and Im looking forward to the next month because its going to be better." It might have to be if St. Louis wants to keep pace with Pittsburgh. The trade for Morneau marked the second big move by the Pirates in five days as they try to beat out the Cardinals and Cincinnati Reds in baseballs tightest division race. Pittsburgh brought in Marlon Byrd and John Buck from the New York Mets on Tuesday. Asked if he was encouraged by the way the Pirates notoriously thrifty front office opened the checkbook to bring in three proven veterans, Burnett couldnt fight back a smile. "Thats what theyre supposed to do," he said. Pittsburgh ranks 10th in the NL in runs scored, one of the main reasons general manager Neal Huntington aggressively pursued Morneau. But the Pirates are averaging 5.2 runs per game during their current six-game homestand and Morneaus arrival gives MVP contender Andrew McCutchen and slugging third baseman Pedro Alvarez some much-needed protection. "Everybody knows we got better with the addition of Justin," Martin said. "Hes an ex-MVP. He knows what hes doing out there. Hes going to give you a productive at-bat and he lengthens the middle of the order." For a night, however, it wasnt McCutchen, Alvarez or Morneau but role players who provided the pop as the Pirates clinched the season series over St. Louis. Burnett got Pittsburgh started with an RBI single in the second, and Jose Tabata followed with one of his own to stake the Pirates to a 2-0 lead. It could have been worse after Lynn loaded the bases before striking out McCutchen to get out of the jam. Lynn wasnt so fortunate one inning later. Alvarez led off with a double, Byrd singled him home and Garrett Jones walked. Martin stepped in and sent a fastball into the front row of seats in right-centre for his second homer in two nights to give Pittsburgh a 6-1 lead. Walker added an RBI triple later in the inning. While Lynn managed to stay in the game, he left after four innings following a miserable start in which he gave up seven runs on 10 hits with three walks and four strikeouts. His ERA rose to 4.29. The deficit proved far too large for a suddenly reeling offence. The Cardinals lead the NL in batting average and runs but have scored just once in their last three games. "Weve had a few balls hit hard, but not a lot," manager Mike Matheny said. "I like what our offence has done over the majority of the season. You dont want to take a couple of games and start making conclusions. Were just going to keep going about it." Burnetts control had something to do with it in front of the second-largest crowd in the 12-year history of PNC Park. Working both sides of the plate effectively, Burnett assured Pittsburgh heads into the final month of a remarkable season in first place for the first time since it won the NL East in 1992. NOTES: Reliever John Axford, acquired on Friday from Milwaukee, pitched a perfect seventh in his Cardinals debut. ... The Pirates have outhomered St. Louis 18-3 in 15 meetings this season. ... St. Louis SS Pete Kozma grounded out while pinch-hitting for Lynn and is hitless in his last 29 at-bats. ... The series concludes Sunday. Joe Kelly (6-3, 2.91 ERA) starts for St. Louis against