Cubs 6, Cardinals 5: Darwin Barney tied the game with a two-run double in the eighth inning and pinch hitter Dioner Navarro followed with an RBI double as visiting Chicago rallied to hand St. Louis its fourth straight defeat.

Barney and Navarro delivered their key hits with two outs for a 5-4 lead while Welington Castillo homered and knocked in a pair of runs for the Cubs. Blake Parker (1-1) pitched a scoreless seventh inning for his first major-league victory and Kevin Gregg allowed Matt Holliday’s second homer in the ninth before nailing down his 25th save.

Holliday also belted three-run homer and finished with four RBIs while Carlos Beltran recorded two hits and an RBI for the Cardinals. Matt Carpenter added two hits and scored twice for St. Louis, which remained four games behind Pittsburgh in the National League Central.

Castillo led off the second inning with a solo blast to left field, giving the Cubs the first run of the contest. Carpenter and Beltran opened the bottom of fourth with singles and trotted home when Holliday lined a 1-1 pitch into the left field seats for his first homer in 18 games.

After Castillo’s sacrifice fly brought the Cubs within a run, Beltran’s RBI double down the right-field line plated Carpenter for a 4-2 lead in the sixth. Trevor Rosenthal (1-3) gave up three runs on two hits and two walks in the eighth and Nate Schierholtz added an RBI single in the ninth off Michael Blazek for the Cubs.

GAME NOTEBOOK: The Cubs, who also beat the Cardinals 3-0 on Friday, sealed their first series victory at St. Louis since Sept. 13-15, 2010. The teams play the finale of the three-game set Sunday. … St. Louis C Rob Johnson had two singles for his first multi-hit game since May 20, 2012 while he was with the New York Mets. … Chicago starter Carlos Villanueva yielded four runs and seven hits over six innings and Cardinals rookie Michael Wacha allowed two runs on five hits over the first five frames.