Byung Ho Park thought his first Twins homer -- a grand slam -- was a double

Byung Ho Park is used to hitting home runs. He hit at least 50 of 'em in his last two seasons in the Korean Baseball Organization, and at this point, mashing baseballs into the ether is old hat. But before Sunday's game against the Rays, he'd never hit one as a member of the Twins. 
And then, with the bases loaded in the first inning, he sent one over the fence for his first Twins home run -- a grand slam. Naturally, his teammates were waiting at the plate to celebrate.

And yes, as you can see above, Park was carrying his shin guard as he crossed home. Did he stop at second in the middle of his home run trot to take if off?
He did. Park explained to MLB.com's Rhett Bollinger: 
"I just thought it was a double because I had my head down and I was running as fast as I could. ... I just kind of stopped and then the umpire was yelling at me, 'Home run. Home run.'"
Watch the slam in the video above -- it was pretty close. 
And hey, when it's your first home run with a new team, things could take some getting used to. But there probably won't be any doubts about the next one.