The Islanders got to Devils goalkeeper Martin Brodeur for four goals on just eight shots over the first 20 minutes.
Anders Lee got the Islanders going with a power-play goal just 3:32 into the game. Bailey then made a steal at the top of the circle, skated in alone and fired it past the 41-year-old Brodeur for a 2-0 lead.
Rostislav Olesz got the Devils on the board before Bailey struck again, firing a backhander past Brodeur with 1:55 left in the period.
I'll be happy, believe me, if we win our last playoff game. Not taking anything away, but we've had a fairly good lead for a while now. It would be more surprising if we didn't get the division. Business as usual.
— Ducks coach Bruce Boudreau after clinching their third straight Pacific Division title