PHILADELPHIA (AP) - Jake Arrieta pitched eight strong innings for his major league-leading 19th win, and Starlin Castro homered to lead the Chicago Cubs past the Philadelphia Phillies 5-1 in the first game of a doubleheader Friday night.
Addison Russell hit a two-run double and Kris Bryant set a club rookie record with his 87th RBI for Chicago, which entered play nine games ahead of San Francisco for the second NL wild-card spot. The Cubs have won six of their last seven.
Aaron Altherr homered for Philadelphia, which has lost 13 of 17.
The nightcap was scheduled to start 30 minutes after the opener of the twin bill, which was necessitated by Thursday night's rainout.
Arrieta (19-6) won his eighth straight start, allowing six hits with seven strikeouts and two walks to become the first Cubs pitcher to win that many in a row since Milt Pappas won 11 consecutive games in 1972. In his last 16 starts dating to June 21, the right-hander is 13-1 with a 1.00 ERA and 115 strikeouts in 117 innings.
The only blemish for Arrieta was Altherr's second-inning solo homer, which halted his streak of consecutive innings without an earned run at 30 2-3.
Adam Morgan (5-6) allowed four runs and seven hits in five-plus innings.
The Cubs went ahead with two two-out runs in the fifth. Dexter Fowler tied the game at 1 when he scored from first on Austin Jackson's double to left, and Jackson reached on Bryant's double to right.
Bryant eclipsed Billy Williams (1961) and Geovany Soto (2008) with the run-scoring hit. His 87 RBIs are tops among rookies in the majors.
Castro, who lost his role as an everyday player to 21-year-old shortstop Russell, belted his eighth homer with two outs in the seventh. It was the 13th RBI in 17 games in Philadelphia for Castro, who is 9 for 16 in his last five games overall.
Ryan Howard of the Phillies went 0 for 4 with a strikeout to extend his career-worst slump to 0 for 31 over his last eight games.
Bryant, who normally plays third base, made his third appearance in left field. Javier Baez started at third.
Philadelphia played its first game since Thursday's firing of general manager Ruben Amaro Jr.
Cubs: C Kyle Schwarber, who has been battling an oblique/rib injury, didn't play.
RHP Dan Haren (9-9, 3.73) takes the mound for the Cubs on Saturday night against Phillies RHP Jerad Eickhoff (1-3, 4.70).