(The Sports Xchange) - A one-out eighth inning home run by Javier Baez gave the Chicago Cubs the lone run they needed in a 1-0 National League Division Series victory over the San Francisco Giants on Friday.

Baez launched a 3-2 pitch into Wrigley Field's left field basket to break open a scoreless pitchers' duel between Giants starter Johnny Cueto and Cubs left-hander Jon Lester.

Cubs closer Aroldis Chapman allowed a two-out double to Buster Posey in the ninth, but got Hunter Pence to ground out to Baez at second to lock down the victory and claim a save.

The victory gave the Cubs a 1-0 lead in the best-of-five series, which resumes on Saturday.

Lester departed for pinch hitter Tommy La Stella with two out in the eighth. He gave up five hits, struck out five and walked none in an efficient 86-pitch outing for the victory.

Cueto, who took the loss, otherwise had a crisp three-hitter but topped 100 pitches by the eighth inning. He struck out 10 while walking none.

The low-scoring game was the sixth straight one-run game between the teams, including four at Wrigley Field in early September.

The Giants threatened with two outs in the fourth when Angel Pagan lined a 3-1 pitch to left for what appeared to be the final out.

Instead, the ball slipped past the outstretched glove of Ben Zobrist for a hit that also advanced Posey to third. Lester escaped the inning as Brandon Crawford grounded to short.

Kris Bryant's one-out double to left in the bottom of the fourth was the Cubs' first hit of the game. But Chicago came up empty as Anthony Rizzo and Zobrist followed with groundouts to second.

Cubs catcher David Ross thwarted potential Giants' threats with two pickoffs. He threw out Gorkys Hernandez at second in the opening inning and then caught Conor Gillaspie leading too far off first base in the third.

Ross lined a long fly to left center in the Cubs' third that would have gone for extra bases except for a sliding catch by Hernandez on the warning track.