Wainwright (2-1) gave up two runs on five hits and struck out six with only one of the runs being earned.
Jason Isringhausen came on to pick up his league-leading sixth save, although he gave up two runs on three hits while doing so.
Carlos Villanueva (1-2) took the loss, surrendering five runs on eight hits over 4 2/3.
Jessica Simpson shares three-way kiss with friends in photo
Teacher apologizes for showing sexual image of herself in class