"It's tough coming to the rink every day when you're losing games," O'Sullivan said. "Tonight was a full 60 minute effort and we got the result we wanted.
"It's a good feeling. Now we don't have to think about the fact that we've lost a number of games in a row. Now we can think about the things that we did well. We're in a difficult spot right now, it's desperation time, really, for our team."
The game was Oilers coach Pat Quinn's first against Toronto since he was fired by the Maple Leafs following the 2005-06 season.
"We probably should have won four of those seven games we lost, but we always found ways not to do it," Quinn said. "And you could tell our guys got scared again after that one goal. But I'm glad we got this win. We needed it for a lot of reasons."
Gilbert Brule opened the scoring with 53 seconds left in the first period, and O'Sullivan connected with man advantages at 10:05 of the second and 2:34 of the third.
Phil Kessel spoiled Deslauriers' shutout bid with 4 minutes left in the third, scoring a power-play goal. Vesa Toskala made 20 saves for the Maple Leafs.
"Sometimes you get the bounces on your side and sometimes they are against you," Toskala said. "There is not much you can do about it."
Toronto has lost four of its last five games.
"We knew they were going to be a desperate team with how things have been going for them of late," Kessel said. "We were in that spot at the beginning of the year. They took it to us right from the start. We didn't get many shots and didn't play our game.
"They played harder than us tonight. We are a forechecking team, that's how we get our chances, and we didn't do enough of that to sustain some pressure."
The Oilers also ended a seven-game home losing streak. ... Oilers defenseman Ladislav Smid played after having X-rays to make sure he didn't break any bones in his hand fighting Calgary's Jarome Iginla on Monday night.
Copyright by STATS LLC and The Associated Press
Arena: Rexall Place Location: Edmonton, Alberta
Referees: Dan O'Rourke, Kevin Pollock Linesmen: Jay Sharrers, Vaughan Rody