CHICAGO -

Drew Stubbs hit a tiebreaking RBI single in the 11th inning on Wednesday night and Cincinnati beat the Chicago Cubs 6-5 hours after Reds manager Dusty Baker left the ballpark for chest X-rays.

Baker was diagnosed with an irregular heartbeat and was expected to stay overnight in a Chicago hospital. Reds head trainer Paul Lessard said the 63-year-old manager would not be with the team today.

Brandon Phillips' lazy popup with two out in the 11th was misplayed by Cubs right fielder David DeJesus, allowing him to reach second. Stubbs then smoked a run-scoring single to left against Alberto Cabrera (0-1).

Logan Ondrusek (5-2) worked out of a bases-loaded jam in the 10th to earn the win. Jonathan Broxton earned his fourth save in six chances since joining Cincinnati in July.