Bates, a Massachusetts native, took a breakout pass from Blake in front of defenseman Jiri Slegr and came in alone on rookie Hannu Toivonen. His quick shot got through for his second goal of the season.
"It was just a great play by Blakey to set me free," Bates said. "I was running out of gas, and I just wanted to put it on net, and maybe Blakey would be there for a rebound or something."
Islanders coach Steve Stirling shook up three of his forward lines, starting with the top unit. It paid off throughout as Oleg Kvasha, now centering new left wing Alexei Yashin and Miroslav Satan on the right, scored his first of the season.
Defenseman Janne Niinimaa also scored in the first period, on assists from Yashin and Satan, for the Islanders who led 2-0 and 3-2.
Joe Thornton tied it for Boston with only 1:01 left in regulation, just after the Bruins pulled Toivonen for an extra attacker. It was the Bruins' fourth overtime loss in six games.
It became even costlier as defenseman Brian Leetch left late in the second period with an injury to his right knee after a collision with Bates. Leetch said it was his first knee injury as a professional.
"My knee is sore, but we'll find out tomorrow," said Leetch as he limped out of Nassau Coliseum without crutches.
Thornton, who also assisted on Nick Boynton's goal that got Boston even at 2 in the second period, flipped a shot into traffic in front. The puck came back to him and he slid another shot that found its way under goalie Garth Snow's stick.
The late goal enabled the Bruins to earn a point for the sixth straight game.
"I'm disappointed but at least we got a point," Toivonen said. "It feels really bad. We're playing good enough to win the games."
Defenseman Chris Campoli gave the Islanders a 3-2 lead 4:39 into the third period by beating Toivonen with a 50-foot wrist shot.
Snow, filling in for regular New York goalie Rick DiPietro (bruised knee), made 29 saves in his second game as a starter. Toivonen stopped 19 shots in his third start in place of Andrew Raycroft, out with an injured hamstring.
For the second straight game, the Islanders couldn't protect a third-period lead at home. They dominated the first half of the first period in which they grabbed a 2-0 advantage.
But former Islanders player Dave Scatchard cut the Bruins' deficit in half with 4:39 left in the first period and Boynton tied it 10:06 into the second off a faceoff win by Thornton.
Snow kept the Islanders from falling behind in the middle period by stopping 16 shots as Boston controlled play. New York led Buffalo 4-3 in the third period Saturday before yielding three straight goals for the Islanders' third loss in four games.
"I think we've played as well as we've played all year tonight," Snow said. "We definitely wanted the two points in regulation, but at least we wound up with them anyway."
Kvasha gave the Islanders the lead just 52 seconds in, scoring from the slot. Niinimaa made it 2-0 at 11:56 off a nice pass from Yashin.
Yashin, a longtime center, was shifted to left wing after playing the position in Russia last season during the lockout. Stirling made the move to give Yashin less defensive responsibility and get him higher in the Islanders zone so he can break out quicker on offense.
"This was the first night I felt really comfortable as a coach," said Stirling, in his second season with the Islanders. "We only took six penalties, and hardly any were bad. If we can continue to do this on a regular basis, we'll be better for it."
- Islanders RW Mark Parrish returned after missing four games with a hip injury.
- Slegr played in his 600th NHL game.
- Scatchard, who took two of Boston's three penalties, scored 81 goals in 4 1/2 seasons with the Islanders from 1999-2004. He has three goals and two assists in his last six games.
- DiPietro could be back Thursday for New York's home game against Pittsburgh.
- Boston LW Brad Isbister, who missed the three previous games with a groin injury, hurt it again in the second period and didn't return.