"The crowd was going crazy," Giants center fielder Aaron Rowand said.
But the euphoria left the park along with opposing pitcher Yovani Gallardo's fifth-inning homer, a three-run drive that broke a tie and carried the Milwaukee Brewers past the Giants, 4-2.
"I feel bad because I took the wind out of the sails for the fans," Johnson said.
The 6-foot-10 left-hander appeared destined to survive the fifth. Bill Hall's two-out, ground-rule double prolonged the inning. The Giants opted to intentionally walk No. 8 hitter Jason Kendall with first base open. Up came Gallardo, who entered the season with two home runs in 49 lifetime at-bats. He delivered No. 3 by hammering a high 1-2 fastball over the left-field barrier.
Asked if he had wanted to fire his fateful pitch to Gallardo another inch or two higher, Johnson mustered a smile and said, "Well, maybe two or three. You know, that's the one bad thing with pitching in a pattern. Maybe he thought I was going to do the same thing I did to him before. His first at-bat, I did throw an elevated fastball and he swung through it. Obviously I just didn't get [the second one] up enough."
Gallardo, the first pitcher to hit a home run off Johnson in his 22-year career, immediately felt the impact of his feat.
"Not too many people get the opportunity to do that," Gallardo said. "Rounding the bases, I got very excited."
Until then, Johnson appeared to have at least a fair shot at recording career victory No. 296, which would have brought him a step closer to becoming the 24th pitcher to reach 300. He struck out two batters in each of the first two innings, generating the excitement usually reserved for an appearance by Tim Lincecum -- who collected his 2008 National League Cy Young Award plaque in a pregame ceremony.
From his perspective in center field, Rowand was duly impressed by the 45-year-old future Hall of Famer.
"He was rolling along, hitting his spots," Rowand said. "He was doing exactly what he wanted to do."
But, as Johnson said, "it kind of gets lost in that one at-bat."
Gallardo made the Giants look lost in several at-bats. They threatened the right-hander on multiple occasions, but went only 1-for-11 off him with runners in scoring position.
Bengie Molina endured the roughest evening, grounding into a double play in the first inning and hitting into an inning-ending force play with the bases loaded and two out in the seventh inning.
The Giants knew they faced a considerable challenge from Gallardo, who at 23 is almost half Johnson's age. Some expected to see Gallardo, not Jeff Suppan, earn the distinction as Milwaukee's Opening Day starter.
"He's arguably their best pitcher," Johnson said. "He has a bright future ahead of him."
Nevertheless, Rowand said, "all in all, I thought our approach against him was pretty good." Rowand could say that legitimately after doubling twice, including a seventh-inning clout toward the 421-foot marker in right-center field that would have been a homer in most other parks. That was the kind of hit that frustrated Rowand last season, his first as a Giant. Wednesday, he grinned and shrugged off the experience, insisting that he'll continue trying to spray line drives in all directions. Even that one.
"When you shy away from trying to hit the ball that way, you kind of become one-dimensional," he said.