Phillips struck home a sweet long-ranger on 73 minutes against Town on an afternoon when five different United players found the net.
Italian defender Dario Del Fabro set United on their way with an 11th-minute opener, heading home following Chris Dawson’s corner.
Six minutes later, United - who had beaten hosts Crewe 2-1 in their previous game - doubled their lead, when Brian Montenegro rounded Joe Murphy before tucking the ball into the back of the net.
Leeds settled the issue four minutes after the break when Dawson sent Murphy the wrong way from the spot after Norwegian midfielder Sondre Tronstad received his marching orders for a deliberate handball offence.
Phillips’ fine strike made it 4-0 and further gloss on the win arrived in stoppage time when Ross Killock headed in.
United: Grimes, Coyle, Killock, Del Fabro, Denton, Purver, Phillips, Adryan (Booker 69), Dawson, Walters, Montenegro (Parkin 64). Unused substitutes: Atkinson, Coker, Skelton.