Chris Davis extended his torrid start with a grand slam and five RBI, and the Baltimore Orioles used a five-run eighth inning to beat Minnesota 9-5 Friday in their home opener.

Davis became the fourth player in major league history to homer in his first four games of the season, joining Willie Mays, Mark McGwire and Nelson Cruz. He is 9-for-15 (.600) with four homers and 16 RBI.

The Orioles trailed 5-4 before loading the bases with one out in the eighth against Casey Fien (0-1). After Adam Jones tied it with an RBI single, Davis greeted Twins reliever Tyler Robertson with an opposite-field shot to left on the first pitch.

The grand slam set off a wild celebration from the sellout crowd of 46,653, many of whom came to welcome back the Orioles from their banner 2012 season, when they ended a run of 14 years of losing with their first playoff appearance since 1997.

Luis Ayala (1-0) allowed two hits in scoreless 1 2/3 innings for the Orioles, who improved to 3-1 after taking two of three from Tampa Bay on the road.

Brian Dozier drove in three runs for the Twins, who were playing their first road game. Minnesota lost three in a row in Baltimore to start last season.