CHICAGO -- Sheer luck is the only explanation A.J. Pierzynski has for his recent power surge.

“That's why it's funny,” he said after the Chicago White Sox's 4-2 win over the Los Angeles Angels on Sunday.. “It's not like I’m trying to hit home runs. I'm trying to put the barrel on the ball and I'm lucky they're going out.”

Pierzynski tied a franchise record on Sunday by hitting a home run in his fifth straight game. What was special about this homer was that it came on his scheduled off day, which lasted seven innings before manager Robin Ventura used him as a pinch hitter with a runner on and the Sox trailing, 2-1.

“We were laughing and joking around,” Pierzynski said. “The guys that are supposed to do that, [Paul Konerko and [Adam Dunn], they were making fun of me and calling me a home run hitter. I'm not supposed to be doing this, so just ride it out as long as you can, enjoy it and have fun with it.”

This was Pierzynski’s third career pinch-hit home run and first since Sept. 8, 2007. The blast raised his home run total to 21 on the season, a career high and also the second most all-time by a White Sox catcher behind Carlton Fisk (37).

The 35-year-old catcher is having one of the best seasons of his career and his continued production at the plate has given backup Tyler Flowers fewer opportunities. The only setback Pierzynski has experienced was an oblique strain that sidelined him for five straight games in late July. In a way, Ventura said that time off probably has benefited Pierzynski.

“He's come back strong ever since that,” Ventura said. “That's part of the duties of catching; it just wears you down. So he has a little more zip in his bat. He's as strong as anybody, so when he hits it it's going to go.”