PITTSBURGH — Neil Walker was looking for a pitch to drive, and he found one.

Walker hit a two-run homer in Pittsburgh's three-run eighth inning and the Pirates beat the Arizona Diamondbacks 4-3 on Sunday to complete a three-game sweep.

Andrew McCutchen hit a leadoff drive in the first and finished with two hits for Pittsburgh, which has won five of its last six home games. The majors' worst team earned its first three-game sweep since May 4-6 against the Chicago Cubs.

"It's definitely been a long while," McCutchen said. "Walker delivered in a big way and put us up. It was good just to be there and be a part of it and just to not give up, keep fighting and get those three wins and sweep."

Pittsburgh (51-98) remains two losses away from its first 100-loss season since 2001 but managed to pick up its first sweep of any kind since taking both games from the Cubs from May 31-June 1.

Jose Tabata hit a run-scoring fielder's choice to cut Arizona's lead to 3-2 before Walker connected against Aaron Heilman (5-8), hitting a drive to center for his 12th homer.

"I was thinking to just try to hit one in the gap somewhere and possibly get a chance to score Jose," said Walker, who had two homers and five RBIs in the series. "And instead I was fortunate enough to get one in the air and hit one on the barrel.

"We know we're not going to make the playoffs but situations like these can bring teams closer together."

Joel Hanrahan (4-1) struck out both batters he faced in the eighth, and Evan Meek worked a perfect ninth for his third save.

Ryan Roberts homered for the last-place D'Backs.