"I thought I was going to throw up in the ninth inning," Brandon Belt said after the historic 10-0 win over the Astros.
Manager Bruce Bochy and company weren't any better in the dugout.
"I'm just like you, I'm a fan," Bochy said. "I got up on every fly ball, I didn't change anything. I stayed in my same place where I sit. I was living on every pitch, too, and pulling for him as hard as anybody."
But after Belt caught third baseman Joaquin Arias' throw to first on Jason Castro's ground ball to send Cain's name into the record books, the nerves were dropped for excited celeration as Cain's teammates mobbed him after the 22nd perfect game in Major League history. It was also the first for the Giants franchise, now in its 130th year of existence.
"When he got that last out, euphoria hit for everybody," Bochy said. "We just went nuts in the dugout. As we should -- we witnessed history."
Cain was emotional after the game, a result of both his accomplishment and his teammates' outpour of support throughout the night.
"I think he understood how much we think of him and the game he just threw," Bochy said. "It's just such a good feeling to see someone achieve a feat like he did, and you realize how hard that is. It's an emotional time."
Despite some close calls this season and throughout his career, Cain completed both a perfect game and his first no-hitter.
"You know every time he goes out there, he's going to give you his best," Belt said. "He's got the stuff to throw a no-hitter every time pretty much, so we knew it was going to come eventually."
Cain's teammates watched as the 27-year-old righty struck out 14 batters, tying him with Sandy Koufax for the most in a perfect game.
"He's so focused," Angel Pagan said. "You see a lot of pitchers who are under a twilight zone, but he's something else. He goes out there and he wants to eat you alive. He has that mentality.
"I've been facing Matt since 2004, and he's one of the best pitchers I faced in the Minor Leagues and in the Majors, as well. I don't have a hit against him yet, I'm 0-fer against him. He's tough to beat, he's a horse. He's a good competitor and he's fun to watch and play behind him."
Giants players compared the game and the AT&T Park atmosphere to the playoff run that ended with winning the 2010 World Series.
"I didn't know if I would ever be a part of one," Belt said of a perfect game. "It really never registered to me that I could be part of a perfect game, and it's one of the coolest feelings in the world."
Belt was especially on edge watching Cain, fearing he had mistakenly thrown off the pitcher's fortune. In between the sixth and seventh inning, Belt found that he had accidentally sat in Cain's spot in the dugout.
"I didn't realize it," Belt said. "He came over and he just stared at me. I was just thinking, 'What is he looking at?' And then I figured it out."
"I was kind of panicking a little bit, but he picked me up."
Jay Lee is an associate reporter for MLB.com. This story was not subject to the approval of Major League Baseball or its clubs.