Jon Sim (power play) scored his fifth goal this season at 7:41 of the second period, which was the eventual game-winner. Bill Guerin scored once.

Doug Weight had two assists and Joey MacDonald stopped 35-of-37 shots for the Islanders, who have won four of their last five games. McDonald stopped all 18 shots he saw in the second period.

Before the contest, the Islanders learned that center Frans Nielsen will miss up to two months with leg injuries he suffered in Friday's 5-2 win over New Jersey.

Mark Mancari and Derek Roy scored for Buffalo. Patrick Lalime was beaten three times on 25 shots in the Sabres' season-high fifth straight loss.

The Islanders were 2-for-5 on the power play, while the Sabres were 0-for-1.