After the Giants held on to beat St. Louis 5-4 in 10 innings, Flannery announced the trio are "now 3-0" when singing the anthem together. The third base coach is 4-1 overall, losing once when he sang with his brother on "Grateful Dead Night."
"We did this two years ago," Flannery said. "And they haven't been together. They're about ready to start a 50th anniversary Grateful Dead, so they kind of split their ways this last summer, and so this might have been the first time they've been together."
Flannery didn't need to sing or shout or say anything else to Brandon Crawford as he rounded third for the game-winning run on Gregor Blanco's 10th-inning bunt to go ahead 2-1 in the best-of-seven series.
In August, Weir cancelled all of the tour dates he had planned through January.
The 66-year-old guitarist, one of the Grateful Dead's founders, said his tour with his current band, RatDog, wouldn't kick off as planned and announced on the band's website that "circumstances have necessitated that all scheduled tour dates for Bob Weir & RatDog are being cancelled." No other details were given.
The trio of Lesh, Weir and Flannery also performed the anthem before Game 2 of the 2012 NLCS against St. Louis.
"Yeah, we'll get him back out there tomorrow," Giants manager Bruce Bochy said with a smile of Flannery's singing.