"I was just trying to be a little bit more quiet and keep my head on the ball," Semien said. "I've been seeing lefties a little bit better since Spring Training, and they threw me a fastball middle in and I put a good swing on it and barreled it up."
Sox manager Robin Ventura said before Thursday's game he thought Semien was pressing a bit at the plate. Prior to the home run, Semien picked up his first RBI with a bases-loaded walk in the sixth after falling behind in the count, 1-2. Semien said that tough seven-pitch at-bat, in which he fouled off a couple of quality two-seam fastballs, seemed to relax him.
"In that situation, [I had] one out, runner on third, which I've had a lot of times and I didn't come through the last couple of times," he said. "So it felt good to get on base and get a run in at the same time."
Semien made a good bid for a hit Opening Day, when he rocked a Ricky Nolasco pitch into the left-center-field gap but was robbed of extra bases by left fielder Josh Willingham, who made an over-the-shoulder catch.
"That's why it's the big leagues, they make plays behind their pitchers just like we do," Semien said. "You've got to earn your hits."
Joe Popely is an associate reporter for MLB.com. This story was not subject to the approval of Major League Baseball or its clubs.