Cueto and Posey were the starting battery, and despite the former's sensational 13-1 record coming into the All-Star break, he exited with a 3-1 deficit after surrendering second-inning home runs to former Royals teammates Eric Hosmer and Salvador Perez.
"This is a game. The game is over with, for me," Cueto told reporters outside the NL clubhouse in the middle of the game. "I'm just going to start concentrating and start the season on Friday."
Home-field advantage was on the line, and that is historically important since the winning league began taking World Series home edge back in 2003. The Giants won in 2010 and '12 after NL All-Star victories, taking advantage by crushing the opponent -- Texas and Detroit, respectively -- in the first two games at AT&T Park. In 2014, the AL won the Midsummer Classic, and the Giants had to clinch in Game 7 at Kansas City.
Speaking of the Royals, Cueto experienced that home-field advantage just last fall when his team capitalized and won the World Series.
Cueto's final line: 1 2/3 innings, five hits, three runs, one strikeout and two homers.
"I would have loved to have been able to get them out, but I just left two pitches up," Cueto said. "When you make mistakes in the big leagues, and you leave pitches up like I did, then you pay the price."
Belt -- the 2016 Esurance MLB All-Star Game Final Vote winner -- entered the game as a pinch-hitter in the eighth and led off by flying to right against AL reliever Andrew Miller of the Yankees. Belt was so thankful just to get that opportunity from the fans that he and his wife, Haylee, bought pizza for the club's entire front office as a show of gratitude for helping.
"It was one of the coolest baseball experiences of my life," Belt said. "I'm just glad I got to come here and enjoy it, and it's something I'll never forget."
Bumgarner was selected and introduced with full honors, but had to be replaced by Bartolo Colon of the Mets on the roster due to his regular-season pitching schedule.
Posey got the start in his fourth All-Star Game and drew a one-out walk against Toronto's Aaron Sanchez in the fifth inning. Anthony Rizzo of the Cubs singled him to third, and Posey then scored on Marcell Ozuna's single to cut the AL lead to 4-2.
Posey was replaced with Washington's Wilson Ramos as a defensive substitution in the bottom of the inning and stayed glued to the top rail of the dugout cheering on his team.
"He is a gamer. You wouldn't find that from stars," said Collins. "After they come out of the game, they like to sit down and relax. I told him if we can bring a catcher back in and he said, 'Hey, I'll be there for you at the end of the game.' So that's the kind of guy he is."
Mark Newman is enterprise editor of MLB.com. Read and join other baseball fans on his MLB.com community blog. This story was not subject to the approval of Major League Baseball or its clubs.