Given a chance to redo that start, Maholm had a five-hit shutout going with two outs and none on in the seventh before the Yankees tied it on Bobby Abreu's two-run single. After McLouth hit his 18th homer to put Pittsburgh back into the lead, Maholm came back with a scoreless eighth.
Maholm, 4-0 in his last eight starts, gave up seven hits and walked one while lasting eight innings for a second successive start. Damaso Marte finished for his fourth save in six opportunities, helping end New York's five-game winning streak.
Jack Wilson, who doubled and singled against Mike Mussina in his first two-bats as Pittsburgh's No. 9 hitter, walked ahead of McLouth's drive into the right-field seats against reliever Jose Veras (2-1). McLouth unsuccessfully tried to bunt on Veras' first pitch, only to homer on the second.
The Pirates won two of three from the Yankees in interleague play, their first two victories against them since the 1960 World Series - a turnaround from past interleague results. The Yankees, 10-8 against the NL this season, are a major league-best 123-87 since interleague play began in 1997 and the Pirates, 6-9 this year against the AL, own the worst record at 63-103.
Despite the Yankees' loss, the AL topped the NL in interleague play for a fifth consecutive season, going 149-103.
Freddy Sanchez, the 2006 NL batting champion who came into the game hitting .226, drove in the Pirates' first two runs with an RBI single following Wilson's double in the third and a sacrifice fly two innings later.
McLouth, the Pirates' lone All-Star, set up that run in the fifth by reaching on a force play, stealing second and moving to third on catcher Jose Molina's throwing error on the play.
Mussina didn't figure in the decision, failing to get 12 victories before the All-Star break for the first time since he was 12-3 in 2002. He gave up nine hits and two runs in six innings, lasting at least six for the eighth consecutive start.
