Davis hit a go-ahead homer in the sixth and connected again leading off the eighth, and the Oakland Athletics beat the Los Angeles Angels 4-2 to open the season Monday night.
Davis notched just the second multihomer game on opening day in Oakland history - Jason Giambi did it in 2000 - to back Kendall Graveman (1-0). The right-hander struck out seven over six innings.
Mike Trout hit a two-run homer in the third inning for the Angels, then Yonder Alonso's RBI single in the fifth tied it at 2.
Davis, who dealt with a sore quadriceps muscle leading up to the opener, connected first against Angels starter Ricky Nolasco (0-1) then JC Ramirez for his 12th career multihomer game. The slugger didn't hit his first home run last season until April 21 then finished with a career-high 42.