Drew Stubbs hit a tiebreaking RBI single in the 11th inning Wednesday night and Cincinnati beat the Chicago Cubs 6-5 hours after Reds manager Dusty Baker left the ballpark for chest X-rays.
A team spokesman said the tests were to "rule out pneumonia." Bench coach Chris Speier brought the lineup card to home plate and there was no sign of the 63-year-old Baker during the game.
Brandon Phillips' lazy popup with two out in the 11th on a windy night at Wrigley Field 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.
Joey Votto reached four times and drove in three runs for the Reds (90-59), who have won three straight to become the second team in the majors to reach 90 wins. Cincinnati also moved a season-high 31 games over .500.
Alfonso Soriano hit his 30th homer for Chicago, which trailed 5-1 after five innings.
Cincinnati lowered its magic number to clinch a playoff spot to one with the Los Angeles Dodgers splitting a doubleheader at Washington. The Reds' magic number for a second NL Central title in three years is three.
The Reds used five straight singles to score three times in the third. Votto drove in a pair with a bases-loaded single to left and Ryan Ludwick singled in Stubbs to make it 4-0.
Votto also doubled in a run in the first.
Reds starter Mike Leake retired his first 11 batters before Anthony Rizzo's two-out single in the fourth. After a walk to Soriano, Starlin Castro singled in Rizzo.
Castro finished with four singles and leads all major league shortstops with 76 RBIs
Soriano hit a long two-run drive onto Waveland in the sixth inning, giving him six career 30-homer seasons, including two with the Cubs. He now has 103 RBIs, one short of matching his career high.
Castro followed with a two-out single and scored on Luis Valbuena's double down the left-field line, trimming the Reds' lead to 5-4. Leake then caught a lackadaisical Valbuena wandering off of second base to end the inning.
The 24-year-old right-hander allowed four runs and six hits over six innings.
The pesky Cubs rallied with two outs in the eighth against J.J. Hoover, who walked three batters - including one that forced in the tying run.
Cubs starter Chris Rusin was tagged for five runs and 10 hits in five innings. The 25-year-old had given up just three runs and nine hits over his last two starts - both of which also lasted five innings.