Greiss, back in goal after watching Jaroslav Halak play the previous four games, robbed Sven Baertschi twice in alone in 30 seconds into the third period, making the initial save with the tip of his right pad, then sprawling to get the paddle of his stick on the rebound.
"He was our best player tonight," Hickey said. "I don't know how many of those goalmouth scrambles we had, and he makes himself really big, spreads out and takes away those stuffs, so we owe this one to him."
Left wing Shane Prince, acquired from the Ottawa Senators before the NHL Trade Deadline on Monday, made his debut for the Islanders on the top line with John Tavares, but was dropped down the lineup by the second period as New York struggled early.
Vancouver had to shake up its lines after top-line right wing Jannik Hansen sustained a rib injury in the morning skate; the Canucks dressed 11 forwards and seven defensemen, with Yannick Weber playing on the fourth line. Hansen will be out at least a week before being re-evaluated, Desjardins said. Forward Brendan Gaunce was called up from the American Hockey League on Tuesday, but didn't arrive in time to play.