Mayfield put New York ahead 2-1 just 14 seconds into the second period when his shot from the right point deflected in off the sticks of Canucks forwards Pius Suter and J.T. Miller.
“The hockey gods reward you sometimes,” Lee said.
Engvall then extended the lead to 3-1 at 2:10, jamming in a rebound at the top of the crease after Lankinen made a good save off Simon Holmstrom in the slot.
Engvall did not play in the Islanders' first seven games this season, instead starting out in the American Hockey League after clearing waivers. He has three points (one goal, two assists) in nine games since being recalled.
“Outstanding,” Roy said. “He was really good. He was at the net. He scored that goal, he had other good chances. He was skating well up ice. That line played really well. Every line played really well, but that line had a really solid night.”
Kyle Palmieri appeared to make it 4-1 at 8:36 of the third period following a turnover in front of the net, but the Canucks successfully challenged the play for offside.
However, Lee did make it 4-1 at 11:42. Horvat beat Quinn Hughes down the right wing and passed back out front from below the goal line to Lee, who was left alone for a quick shot from the low slot.
Dobson shot into an empty net at 17:54 to make it 5-1.
Tyler Myers scored on a wrist shot from the right circle at 18:34 for the 5-2 final.
“We played a really solid game,” Lee said. “Our [defensemen] moved the puck really well. They were quick. They broke the puck out really well. It's a good forechecking team with a lot of skill, and I thought they did a good job of getting the puck up to the forwards and us being available in return, and that led to some sustained puck control a little bit, and we did a good job on our chances of putting it in.”
NOTES: Islanders defenseman Grant Hutton had two assists, the first two of his NHL career (24 games). ... New York was 1-for-5 on the power play. Vancouver was 0-for-1 despite pulling Lankinen to create a 6-on-4 on their only power play with 4:54 left in the third period. ... Hughes had his point streak end at five games (one goal, seven assists).