Rookie Ryan Lavarnway belted his first two career home runs and drove in four runs to help Boston outlast the host Baltimore Orioles 8-7 on Tuesday and send the Red Sox into the final day of the season tied for the American League wild card lead.

Jacoby Ellsbury and Marco Scutaro each hit two-run homers to keep the Red Sox deadlocked with Tampa Bay and set up a critical regular-season finale Wednesday at Baltimore.

Lavarnway, making his first major league start at catcher, hit a three-run homer in the fourth and a solo shot in the eighth as Boston won for only the fifth time in 20 games.

Alfredo Aceves (10-2) pitched 3 2/3 innings in his third relief appearance in as many days to match his career-high win total and improve to 24-3 lifetime.

Jonathan Papelbon allowed a run in the ninth before earning his 31st save after the Orioles had closed within 8-6 with two runs in the eighth off Daniel Bard.

Ellsbury's 32nd homer, his fourth in as many games, put Boston ahead 2-1 in the third before Lavarnway clubbed a three-run shot off Zach Britton (11-11) in his 32nd career at-bat for a 5-1 cushion.

Matt Wieters hit a two-run homer and Adam Jones added a solo shot for the Orioles, who lost to Boston for the second time in six meetings over the last nine days.