So for Zito to lead the way in the Giants' Major League-leading 12th shutout raised the team's hopes of weathering Johnson's absence.
"I came here to help this team win, and I haven't done that to the best of my ability," said Zito, who's 26-38 as a Giant. "It's important that I step up and stay focused on what I have to do and pick up slack while Randy's out."
Right-hander Sergio Romo acknowledged Zito's impact in the wake of Johnson's trip to the disabled list.
"It's quite a blow, because he is Randy Johnson. But we all know that we have a job to do," said Romo, who earned his first career save Tuesday. "For Zito to be able to perform the way he did to give us a boost ... he gave us an even bigger boost today."
Zito reminded witnesses how he won the American League Cy Young Award with Oakland in 2002. Confronting a Marlins lineup lacking All-Star shortstop Hanley Ramirez, the National League's leading hitter who missed his third consecutive game with a sore right hip flexor, Zito faced one batter over the minimum through five innings and allowed one runner to reach scoring position during his 8 1/3-inning stint. That happened in the sixth inning, when opposing pitcher Josh Johnson singled and Emilio Bonifacio walked with one out. Zito responded by retiring Wes Helms on a fly to right field and Dan Uggla on a popup to first base.
Everything looked easy for Zito (5-8), who walked only one and struck out six. But, he said, "For me, it was a grind every pitch. I had to keep my focus every pitch and make sure I was doing what I was supposed to be doing."
Catcher Bengie Molina confirmed that Zito accomplished this.
"He mixed up the curveball, slider, changeup -- everything was working," said Molina, who drove in the Giants' first run with a fourth-inning sacrifice fly.
The view from the Marlins' side looked no different.
"He changed speeds very well," Helms said of Zito. "He didn't leave anything over the middle of the plate. If he did throw a fastball that was hittable, it was either in, just enough for a strike, or away just enough to get that fly ball or that ground ball. He was like the Zito of old.
"He's kind of like Jamie Moyer: He's got to put the ball where he wants to to have success, and he did that tonight. He kept every hitter off-balance."
Having thrown 101 pitches entering the the ninth inning, Zito seemed within reach of his fifth career shutout and first since April 18, 2003, against Texas. That also happened to be Zito's last nine-inning complete game. But when Helms singled with one out, Giants manager Bruce Bochy sprang from the dugout and summoned Romo -- not Brian Wilson, whom the Giants planned on resting after his arduous 37-pitch save Monday.
Bochy wouldn't let Zito work himself into a jam.
"He was going one hitter at a time," Bochy said. In a refreshing turn of events, the AT&T Park crowd, which typically finds ways to boo Zito, turned its wrath on Bochy, since fans wanted to see the left-hander finish what he began.
"It's nice to get booed when you're taking him out. That's a good thing," Bochy said.
It was even better for the Giants when Romo struck out Uggla and Jorge Cantu to conclude the brisk two-hour, five-minute contest, San Francisco's second-shortest game of the season.
Zito clearly wanted to finish the game yet understood Bochy's move. "I haven't quite earned the right to get out of my own jams late in a lot of games this year," said Zito, who has eight quality starts in 17 outings and a 4.43 ERA. "That's something I have to earn back, the respect to do that."
The Giants needed each of Zito's zeroes, given the presence of Johnson, another All-Star who was 4-0 with a 3.00 ERA in eight starts since his last loss May 19. But Juan Uribe, who was simply trying to hit a sacrifice fly or a productive grounder with Edgar Renteria on third base and one out in the fifth inning, extended the Giants' 1-0 lead by clobbering a 1-2 pitch from Johnson (7-2) for his third home run of the season.
"When you go into the game and face an All-Star pitcher, you're not thinking that he's better than me," Uribe said through a translator. "You just go out there and do your job and make contact."