Anton Forsberg made 26 saves for the Senators (14-22-4), who were coming off a 3-2 overtime win against the Edmonton Oilers on Monday.
"Obviously, playing a back-to-back, all that stuff, that's all part of playing in the NHL," Holden said. "Everybody has to play these games, and that's something that I think as we play more of them, you learn how to play these games. You need to make sure you're taking what you're given. Sometimes you have to just change a little of how the game is going to how you're playing. So it's still learning stuff, I think."
Holden gave Ottawa a 1-0 lead when his shot from the left circle trickled in off Sorokin's shoulder.
Anthony Beauvillier tied it 1-1 at 18:07 of the first, jamming a loose puck near the crease five-hole on Forsberg shortly before a power play expired.
Sorokin kept the game tied when he stretched out his left pad to make a save against Alex Formenton on a breakaway at 7:35 of the second.
"We haven't really had the best starts in the past couple of games, but 'Soroky' was good all game," Beauvillier said. "He kept us in the game, big saves at key moments. He gave us a chance to win again tonight."
Wahlstrom then scored on a rebound after he redirected Zdeno Chara's shot to give the Islanders a 2-1 lead at 8:42, and Barzal made it 3-1 with a one-timer from the left circle off a cross-ice pass from Mayfield at 15:50.