Randy Johnson found out the hard way in his Giants debut Wednesday, when he surrendered a two-out, two-strike, three-run home run to Gallardo that snapped a tie and gave the Brewers a 4-2 win at AT&T Park.
According to the Elias Sports Bureau, Gallardo became the first pitcher ever to homer off Johnson, a five-time Cy Young Award winner. Including Gallardo's third-inning strikeout, Johnson had faced an opposing pitcher 506 times without allowing a home run.
So which will Gallardo remember more: the win or the homer?
"The win," Gallardo said without a flinch. "That's the main thing."
Everyone else will remember the home run.
The teams were tied at 1 entering the fifth inning, when Johnson recorded two outs before Bill Hall reached on a ground-rule double. With first base open, Johnson intentionally walked catcher Jason Kendall to face Gallardo. On a 1-and-2 pitch, a high fastball that didn't get quite high enough, Gallardo hammered a pitch deep into a service tunnel down the left-field line.
"Forget about him being a pitcher," said Brewers manager Ken Macha, who notched his first Milwaukee win. "That ball was tattooed for a hitter. It was way out."
Gallardo's Brewers teammates knew he would be no easy out.
"Nobody said anything, but we kind of knew that it's not as easy as you might think walking Kendall to face Yo," said Carlos Villanueva, who notched the save Wednesday after a 1-2-3 ninth inning. "I think they know. But Randy would rather face a pitcher than a hitter any time. He just didn't get it up enough.
"It's not surprising to us. He can hit. We were expecting a hit, not an absolute bomb."
Gallardo entered the year with two home runs in 49 career at-bats. He homered off Arizona's Doug Davis on Aug. 20, 2007, and followed with another off Pittsbugh's Tony Armas two starts later. Hitting one off a five-time Cy Young Award winner was something altogether different.
"Growing up watching him pitch, it's one of those things," Gallardo said. "He's a great pitcher. Not too many people get the opportunity to do that. Rounding the bases, I was very excited."
Davis, incidentally, surrendered Johnson's only career home run in September 2003, when Davis was pitching for Milwaukee at Miller Park.
Adam McCalvy is a reporter for MLB.com. This story was not subject to the approval of Major League Baseball or its clubs.