A hat-trick from Marco di Vaio has inspired Montreal Impact to a 4-2 win over Philadelphia Union.

The result takes the Canadian team to within one point of MLS Eastern Conference leaders New York Red Bulls, while Philadelphia remain fifth in the Eastern Conference.

The Italian opened his account at the Saputo Stadium in the second minute, but Montreal were pegged back almost immediately by Jack McInerney's fifth-minute strike.

Di Vaio then scored two goals in the space of four minutes to see his team head into the break 3-1 up.

Antoine Hoppenot's 68th-minute strike gave the Union hope, but that was quickly extinguished by Andrew Wenger six minutes later.

Sebastien Le Toux's goal six minutes from time set up an interesting finish, but Blake Smith's goal deep into injury time put to bed any nerves.