Pirates 7, Cubs 3: Neil Walker homered among three hits, scored twice and knocked in two as host Pittsburgh clinched its eighth straight series victory over Chicago.

Josh Harrison added two hits and two RBIs and started a triple play for the Pirates, who have won eight of their last 10 and are two games up on Milwaukee for the second National League wild card and 3 1/2 games behind NL Central leader St. Louis. Edinson Volquez (12-7) allowed three runs -- one earned -- over seven innings to improve to 7-0 against the Cubs.

Jacob Turner (5-10) was tagged for seven runs and seven hits in 4 1/3 innings for the Cubs, who have lost eight of nine. Chris Valaika and Chris Coghlan each doubled for the Chicago, which had only two baserunners after the fourth inning.

The Cubs took an early lead on Matt Szczur's infield single and Volquez's throwing error in the second, and sacrifice flies from John Baker and Chris Coghlan made it 3-0. Chicago had a chance to add on in the fourth with two on and none out, but Szczur hit a sharp grounder that Harrison fielded a step from the bag at third and sent around the horn to end the inning.

Walker's solo shot put the Pirates on the board in the fourth, and they sent 12 men to the plate in the six-run fifth inning. Harrison started the outburst with a two-run double that tied it at 3, and Travis Snider and Walker added RBI doubles before Gaby Sanchez and Gregory Polanco tacked on run-scoring singles.

GAME NOTEBOOK: Walker's 20 home runs are the most in a season by a Pirates second baseman, surpassing Bill Mazeroski's mark of 19 in 1958. … Pittsburgh's last around-the-horn triple play was July 23, 1979, while the Cubs last hit into a triple play May 14, 2000, at Montreal. … The Cubs fell to 0-74 when trailing after eight innings.