The Pirates found the perfect recipe for winning baseball games Tuesday night: Hit five home runs and chase the starting pitcher from the game before he can finish the second inning.

The Pirates pounded Seattle starter Joe Saunders, tagging him for six earned runs before he could record six outs in an eventual 9-4 victory against the Mariners at Safeco Field.

Saunders was chased from the game after just 1 2/3 innings, having surrendered three homers in the second inning as the Pirates (47-30) cruised past the Mariners (34-44) for their fifth consecutive victory.

The five homers in the game were the most since the Pirates hit five home runs against Milwaukee on July 22, 2009.

"We had some power jump out there again," manager Clint Hurdle said. "It's been a nice sequence of game. I felt confident the offense would pick up because they're capable, and they're showing their capabilities now."

For the first time since 1992, the Pirates are 17 games over .500.

Starling Marte led the Pirates' offense with a pair of home runs, his first career multi-homer game, and sprinted out a triple. He scored three times in the win.

"There is a power tool there," Hurdle said of Marte. "And it is legit."

Both of Marte's homers were first-pitch fastballs that landed some 400-odd feet from home plate. And when Marte's at-bat, he's aggressively looking for that first pitch fastball.

"Oh yeah," he said. "Everybody likes first-pitch fastballs right down the middle."

Pirates starter Jeff Locke was effective, allowing two earned runs on four hits in seven innings. He started the game a bit erratic but settled into a nice groove.

Locke said it felt like it had been a long time since he took the mound last -- June 19 against the Cincinnati Reds. He even mentioned to the coaching staff he felt a bit weird in the early going, Hurdle said.

"I felt good once the game got going along, breaking ball got a little tighter as the game got going along," Locke said. "And I started to have a bit better command."

His shutout streak was snapped in the second inning, but he earned his team-leading seventh victory of the season.