Petrucci saw a drive blocked at the start of the second half while Scott Wootton made a tremendous saving tackle to thwart Lestienne after he was teed up by Gudjohnsen. Ryan comfortably held a curler by Petrucci and Joyce decided to make a tactical reshuffle with Cole shifting to right-back and Ben Pearson and Lawrence getting a taste of the action.
The Belgian side should really have gone ahead but spurned a couple of gilt-edged chances, firstly when Refaelov's superb turn released Lestienne and then when Lestienne unselfishly squared to Timmy Simons. However, on both occasions, the ball was blazed wildly over Sam Johnstone's bar.
Andreas Pereira almost carved out an opening at the other end but his delightful chipped pass was agonisingly out of the reach of Petrucci, who broke forward through the middle. Predictably, it was Petrucci who had a hand in the winner with 11 minutes left as he guided the ball into the path of Lawrence, who finished calmly, prodding beyond Ryan.
A flare-up led to the referee instructing Joyce to substitute Tunnicliffe and his replacement, the impressive Jack Barmby, almost added a second but Ryan won a one-on-one duel and Pereira's drive from the rebound deflected for a corner. Both sets of players embraced sportingly at the end of a feisty encounter.
United: Johnstone; Grimshaw (Lawrence 53), Thorpe, Wootton, Vermijl; Cole, Ekangamene, Tunnicliffe (Barmby 82), Petrucci, Bebe (Pearson 53); Macheda (Pereira 63). Subs not used: Gollini, Rowley, Love, Wilson, Rothwell.