Cubs 4, Pirates 3: David DeJesus snapped a tie with an RBI single in the eighth inning and Jeff Samardzija tossed his first career complete game in his final start of the season as visiting Chicago clinched its first series victory since Aug. 24-26.
Alfonso Soriano homered for the Cubs, who have won consecutive games for just the second time since late July. Chicago had lost three straight series since taking two of three from Colorado.
Pedro Alvarez recorded two of the four hits by the Pirates, who have lost six of eight. Pittsburgh remained 1 1/2 games behind St. Louis for the second wild-card spot in the National League. The Cardinals dropped a 6-3 decision to Milwaukee on Saturday.
After pinch hitter Jeff Clement forged a 3-3 tie with an RBI single in the seventh, the Cubs came right back to regain the lead. Welington Castillo led off the eighth against Jason Grilli (1-5) with a base hit and scored four batters later on DeJesus' second hit of the game.
Samardzija (9-13) allowed three runs - two earned - and four hits while walking one and striking out nine. The right-hander, who had lost five of six decisions, is being shut down for the year as he's thrown 174 2/3 innings after pitching 169 2/3 frames over his first four major-league seasons.
Pittsburgh jumped out to an early lead on Alvarez's two-run single in the first inning. But Alfonso Soriano led off the second with his 27th home run, Tony Campana scored on a double-play grounder an inning later and Luis Valbuena plated Campana with a sacrifice fly in the fifth for a 3-2 advantage.
GAME NOTEBOOK: Cubs manager Dale Sveum's plan worked as Campana went 2-for-3 and scored twice after being inserted into the ninth spot in the batting order. ... Chicago C Steve Clevenger served the one-game suspension he received earlier in the day for "aggressive actions and fighting" during a bench-clearing incident against Washington on Thursday. ... Pittsburgh RHP Jeff Karstens threw a bullpen session Saturday and is tentatively scheduled to pitch a simulated game on Tuesday, barring any complications in the interim. Karstens is battling back from a strained right hip flexor.