Chicago snapped a two-game skid and handed the Islanders their first regulation loss this season.
The Blackhawks jumped in front on goals by Joakim Nordstrom and Jonathan Toews, but the Islanders managed to tie it by the end of the opening period. Josh Bailey and Kyle Okposo both scored in the final minute of the stanza with Okposo's goal coming a mere five seconds prior to the horn.
Handzus put a wrist shot past Kevin Poulin 6:45 into the second to complete the scoring. Poulin made his first start of the campaign.
Nikolai Khabibulin earned the win by stopping 17-of-19 shots.