Rusney Castillo showed some power Thursday.

Castillo crushed his first major league home run — a three-run shot — in the third inning as the Boston Red Sox defeated the Tampa Bay Rays 11-1 at Fenway Park. The blast landed in the Monster seats, offering a glimpse of what the Cuban outfielder could be capable of while playing in Boston for the foreseeable future.

Castillo nearly added his second homer in the seventh inning, as he planted a double off the wall and later scored from second base on Bryce Brentz’s single into left field. The 27-year-old finished the game 2-for-4, marking the first multihit game of his big league career.

Castillo, who signed a seven-year, $72.5 million contract with the Red Sox last month, has reached base in six of his seven games with Boston. He’s hitting .222 (6-for-27) with four RBIs and two walks.

Christian Vazquez also launched his first major league home run Thursday.