ST. LOUIS -- Cardinals' co-ace Adam Wainwright had his start complicated by an error and a surprise homer as he and the Cardinals tumbled into a 6-1 loss to the Cincinnati Reds on Saturday at Busch Stadium.

The loss knotted this weekend's series, 1-1, and it gave the Reds back their eight-game lead in the NL Central.

Wainwright allowed five runs (two earned) in five innings, and the righthander failed in his fourth attempt to win his 18th game. Wainwright has lost his previous four starts, and he has not won since the Cardinals sweep in Cincinnati in early August. The team's plummet from first place in the division corresponds with Wainwright's difficulty winning.

Cincinnati lefty Travis Wood proved to be a mix of ingredients that Cardinals usually struggle against: A rookie. A lefty. A pitcher who they don't have much video on. A lefty.

Wood held the Cardinals to one unearned run through his seven innings of work. He struck out three and allowed five hits. Wood also hit the first major-league homer of his career, tagging Wainwright for a solo shot in the fourth inning.

The Reds scored three runs in the first inning, and all of them were unearned. The rally was aided by a fielding error by Aaron Miles.

Cincinnati's early lead was enhanced by the tricky hitting conditions that invaded Busch for the middle innings. Shadows stretched across the field, leaving the pitcher in silhouette and also splashing a strip of sunlight between the hitter and the pitcher. Neither team scored from the bottom of the fourth through the bottom of the eighth as the sun lowered.

Miles and right fielder Nick Stavinoha were in the lineup in place of Skip Schumaker and Colby Rasmus, respectively, because of Wood's splits against lefties. Wood has yet to allow an extra-base hit to a lefthanded hitter this season in the majors. Miles and Stavinoha combined to go 0-for-7 with two strikeouts.

The series finale is Sunday at Busch Stadium with the Cardinals starting Chris Carpenter against the Reds' Homer Bailey.

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