Tampa Bay has won six straight and has lost just once in its last 13 games. The Rays have a 13-1 home record this season and own baseball's best record at 19-8.
The Rays built a 7-1 lead through four innings and turned things over to David Price (5-1), who struck out a season-best 12 batters over eight innings.
Price gave up three hits and a walk, surrendering only a second-inning run on Kurt Suzuki's double.
Tampa Bay took the lead with a three-run third that featured a two-run single from Luke Scott. Molina's homer came in the fourth, his first of the year.
B.J. Upton had a run-scoring double in both the third and fourth innings.
All seven runs were scored against Tyson Ross (1-2), who allowed nine hits in just 3 1/3 innings. Oakland had won its previous two games.