Pascal Dupuis scored 9:56 into overtime to give the Pittsburgh Penguins a 4-3 comeback win over the Ottawa Senators that secured a 4-2 series win and a place in the second round of the NHL playoffs. The Senators led 3-0 in the second period and looked set like forcing a deciding Game 7. Ottawa appeared to go up 4-1 in the frame, but lost a goal to video replay when it was determined the puck crossed the line after the net was knocked off its moorings. Pittsburgh's Matt Cooke scored his second of the game with 7:36 left in regulation to tie it 3-3. Bill Guerin scored earlier in the third. Matt Cullen and Daniel Alfredsson each had a goal and an assist for Ottawa, which had won Game 5 in triple overtime to stave off elimination. Pascal Leclaire made 38 saves, and Chris Neil also scored for the Senators. Marc-Andre Fleury stopped 28 shots as the Penguins won for the eighth time in nine playoff series, with the only loss in that stretch being to Ottawa in the first round in 2007. Sharks 5, Avalanche 2: In Denver, San Jose also made passage to round two by beating Colorado in Game 6. Joe Pavelski scored two goals, including the tiebreaking tally midway through the third period. The tying goal was soon followed by Dan Boyle's go-ahead effort. Devin Setoguchi and Douglas Murray added empty-net goals in the final minute after the Avalanche pulled goalie Craig Anderson for an extra skater. Marek Svatos and Brandon Yip scored for Colorado. Evgeni Nabokov was steady in net for the Sharks all night, but not very busy as he stopped just 16 shots. Anderson finished with 29 saves. Blackhawks 5, Predators 4, OT: In Chicago, Patrick Kane tied the game with just 13.6 seconds left and Marian Hossa scored the overtime winner as Chicago beat Nashville to take a 3-2 lead in their series. Chicago can advance in the Western Conference playoffs with a win at Nashville Monday. The Blackhawks blew a 3-1 lead, and the Predators went ahead 4-3 with two third-period goals by Martin Erat. The Predators are the only team in this year's playoffs without a power-play goal. Their latest failure with the game on the line pushed the drought to 0 for 21 with the advantage.