PITTSBURGH - Jeff Locke felt like he was back home on a cool, damp night.

Locke pitched into the seventh inning for just the second time in 10 starts, fill-in left fielder Josh Harrison had four hits and Michael Morse hit a pinch-hit grand slam as the Pittsburgh Pirates rolled to a 10-2 victory over the Milwaukee Brewers on Saturday night.

Locke (8-10), a native of New Hampshire, worked 6 1/3 innings and allowed only one run and three hits as the Pirates (85-56) won for the sixth time in nine games and drew within 2 1/2 games of the first-place St. Louis Cardinals in the National League Central.

It is the closest the Pirates have been to St. Louis since they were also 2 1/2 back at the All-Star break after winning three of four from the Cardinals at Pittsburgh.

"Growing up where there is snow on the field, rain all the time, fields are terrible all the time, it's fun because it's a little gritty," Locke said. "You just hope they don't have to pull the tarp and fortunately they didn't have to tonight."

Locke struck out seven and walked two after losing consecutive starts and four of his last five decisions. The left-hander lowered his home ERA to 3.46 in 88 1/3 innings, compared to 5.89 on the road in 68 innings. Pirates starters have a 1.64 ERA in the last nine games.

He also threw first-pitch strikes to 18 of the first 24 batters he faced.

"It was committing to 100 percent on each pitch," Locke said. "(Catcher Francisco Cervelli) and I talked before the game and we were on a good page about being aggressive early in the count and changing speeds to keep them off balance."

Morse's slam came off left-hander reliever Cesar Jimenez in the seventh inning and extended the Pirates' lead to 10-1. It was Morse's first home run since the Pirates acquired him July 31 from the Los Angeles Dodgers in a trade and the fifth slam of his 11-year career.

Harrison tied a career high for hits as he went 4-for-4 with a walk while filling in for left fielder Starling Marte, who was sidelined by a stomach ailment. It was the ninth four-hit game of Harrison's five-year career.

"I'm ready to play every day," Harrison said. "If I'm not in the (original) lineup then I'm still always ready for certain cases like today."

Third baseman Aramis Ramirez, acquired from the Brewers on July 23 in a trade, hit a pair of run-scoring doubles, including one during a five-run third inning, off rookie right-hander Zach Davies (1-1) to stake the Pirates to a 6-0 lead by the fourth inning.

Davies was knocked out in the fourth after Ramirez's second double as the Brewers (62-80) assured themselves of a third straight season with at least 80 losses with their fifth defeat in seven games.

Davies, making his third major league start, gave up six runs and six hits with five walks and three strikeouts, taking his first career loss after notching his first win Monday over the Marlins at Miami.

"Did a lot of work between the first start and the second start, and it kind of went out the window," Davies said. "That's disappointing. But at the same time, it's work. It's going out there and doing your job, making sure you're getting better each time out. There's always something to work on."

The Brewers' runs scored on second baseman Luis Sardinas' sacrifice fly in the seventh and Ryan Braun's run-scoring double in the eighth.

The Pirates batted around in five-run third inning to break a scoreless tie.

Center fielder Andrew McCutchen singled in the first run and Ramirez followed with an RBI double Cervelli had an RBI single and another run scored on center fielder Domingo Santana's fielding error and shortstop Jordy Mercer brought home the final run on a fielder's choice grounder.

Ramirez hit another RBI double in the fourth inning to extend the lead to 6-0 and help the Pirates tighten up the division race.

"We're just going to keep playing," Pirates manager Clint Hurdle said. "The season is going to play itself out and we've just got to keep working on getting better and trying to win some games.

NOTES: Pirates LF Starling Marte was scratched because of gastroenteritis. He did not start Friday night because of left shoulder discomfort after being hit by a pitch Thursday night. ... Brewers C Jonathan Lucroy (concussion) missed his fourth straight game, though he was able to take dry swings. Lucroy was examined by noted concussion authority Mickey Collins on Saturday at the University of Pittsburgh Medical Center, but there is no timetable for his return. ... The four-game series concludes Sunday, with Milwaukee rookie RHP Taylor Jungmann (9-6, 2.87 ERA) facing Pittsburgh LHP Francisco Liriano (10-7, 3.28).