Tomas Vokoun made 27 saves and stopped three of the Sharks' four shootout attempts to remain unbeaten in his last six starts against San Jose. Alexander Radulov scored in the third period and again in the shootout as the Predators earned their league-best 43rd victory.
Evgeni Nabokov made 28 saves for San Jose and forced the shootout with a stunning glove save on Paul Kariya with a second left in overtime, but the Sharks still lost for the sixth time in eight games.
Guerin, acquired Tuesday from St. Louis in a deadline deal to add toughness and experience to a young team, wore No. 13 and looked active on a line with MVP Joe Thornton and Jonathan Cheechoo. But Nashville kept the big-name line off the scoreboard.
After Martin Erat and Radulov scored power-play goals in the third period to put Nashville ahead 3-2, rookie Sharks defenceman Marc-Edouard Vlasic tied it with a wrist shot through traffic with 4:08 left in regulation.
Steve Bernier and Matt Carle also scored for the Sharks, who played without injured captain Patrick Marleau and defenceman Scott Hannan in just their fourth overtime game of the season.