Cubs 9, Reds 4: Nate Schierholtz knocked in three runs and Anthony Rizzo belted a two-run homer as visiting Chicago pulled away from Cincinnati to gain a split in the rain-shortened two-game series.Starlin Castro contributed two doubles, a single and knocked in a run while Welington Castillo had three hits and Emilio Bonifacio added two hits and an RBI for the Cubs. Chicago starter Edwin Jackson (2-2) battled through 5 2/3 innings, allowing four runs on five hits to beat the Reds for the second time this season.Todd Frazer knocked in a pair of runs, Zack Cozart had two hits and Brayan Pena homered for the Reds, who lost for the fourth time in five games. Cincinnati starter Tony Cingrani yielded three runs on six hits over four innings and Nick Christiani (0-1) took the loss after giving up two runs in two frames.Mike Olt's fielder's choice and a Schierholtz sacrifice fly put the Cubs in front 5-3 in the top of the fifth before Brandon Phillips' two-out RBI single in the bottom of the frame closed the gap. Schierholtz added insurance with a two-run single in the ninth and Chicago added two more on an error and Bonifacio's RBI double. Rizzo hammered his two-run blast to left-center field in the top of the first inning before Frazier doubled home two in the bottom of the frame with two outs to tie it. Pena led off the second with his solo blast over the right-field fence, but Castro countered with an RBI single in the third.GAME NOTEBOOK: Castro is 9-for-20 with two homers and four RBIs batting cleanup this season after going 3-for-4 on Wednesday. … Reds LHP Aroldis Chapman is scheduled to throw one inning with Class A Dayton in his first rehabilitation outing Thursday after the team's closer was hit in the head by a batted ball March 19 at spring training. … Rizzo walked four times and scored three runs while OF Junior Lake had two hits and two runs scored for the Cubs.