Blackhawks fans don't need to be told what Antti ­Niemi can mean to a team. Neither do San Jose Sharks fans, for that matter. The former Hawks goalie, who joined San Jose in the offseason after the Hawks declined to match his arbitration award, derailed the Sharks' postseason last year with a stellar performance in the Hawks' four-game sweep in the Western Conference finals. This season, Niemi went from Shark slayer to being a thorn in the side of his former teammates with victories over the Hawks in their first three meetings. The Hawks got a measure of revenge against Niemi on Monday as they put four past him on 18 shots to chase him with 12:35 left in the second period to the cheers of the fans who used to applaud him. Viktor Stalberg scored in the first period, and Marian Hossa had two goals in the second before Jonathan Toews added a third in the period to finally chase ­Niemi. He had been on an impressive run as the Sharks entered the game with an 18-3-3 record in their last 24 games, with Niemi claiming all but one of those victories. "He's been a very motivating factor for us, very solid down the stretch, an absolute workhorse," Sharks coach Todd McLellan said before the game. In 15 starts from Jan. 15 through Feb. 20, he posted more wins (11), more shutouts (three), a better save percentage (.939) and a lower goals-against average (1.77) than any other goalie in a 15-game stretch in franchise history.