Chicago, IL (SportsNetwork.com) - Dexter Fowler went 3-for-4 with two RBI to power the Chicago Cubs to a 6-2 victory over the Pittsburgh Pirates in the second of a three-game set on Tuesday.

Starlin Castro finished with three hits, two runs scored and an RBI, while Junior Lake, Kris Bryant and Addison Russell also drove in a run apiece for the Cubs, who won their fourth straight game.

Starter Travis Wood (2-1) was solid in the win, surrendering just two runs on five hits with no walks and nine strikeouts in seven innings of work.

"When your starting pitchers go deep into the game, all of a sudden your bullpen gets better," Cubs manager Joe Maddon said. "It's an easy equation."

Starling Marte provided a two-run homer for the Pirates, who have dropped two straight on the heels of a five-game win streak.

Jeff Locke (2-1) was tagged with the loss after giving up six runs -- five earned -- on eight hits and three walks over 3 2/3 frames.

"You have to be able to get ahead of these guys and try to put them away as soon as you can," said Locke. "It kind of slipped away."

The Cubs opened the scoring with three runs in the second inning. Castro and Lake each singled to place runners on first and third to open the frame. Russell ushered in Castro on a liner to left field for an RBI double and Fowler followed with a two-run single to shallow left.

With two outs in the third, Castro reached second after third baseman Josh Harrison's throw to first sailed into the crowd. Lake took advantage of the blunder by doubling to left for a 4-0 game.

Marte cut the deficit in half by stroking a 2-0 fastball just over the wall in left for a two-run homer in the fourth, bringing home Andrew McCutchen, who got aboard with a one-out single.

With runners on first and second, Bryant ended Locke's outing in the bottom half with a run-scoring single and Castro followed suit against Antonio Bastardo for a 6-2 lead.

Zac Rosscup and Jason Motte each provided an inning of perfect relief to ensure the win.

Game Notes

The Cubs won four straight games for the first time since a five-game run from June 3-7 of last season ... Chicago leads the season series 4-2 ... The Cubs will send pitcher Kyle Hendricks to the mound against Gerrit Cole in Wednesday's finale.