Wolverhampton Wanderers have picked their first home victory over Huddersfield Town in 27 years to move into the Championship playoff places.
The Terriers, who had not lost at Molineux since 1988, threatened in the early minutes as Mustapha Carayol found space to shoot, but his low drive was comfortably gathered by Emiliano Martinez.
Moments later, Dean Whitehead was denied by another save from Martinez before Benik Afobe failed to convert a chance at the other end.
However, Wolves edged in front midway through the half as McDonald weaved his way through two defenders and, after a quick one-two, the midfielder curled a low shot past the despairing dive of Jed Steer.
Within moments of the restart, Kenny Jackett's side almost added a second as Dominic Iorfa crossed for James Henry, whose header drifted inches wide.
Afobe was then denied by strong stop from Steer, but the ex-Arsenal frontman doubled his side's advantage on 66 minutes after Adam Le Fondre squared the ball into his path before the 22-year-old slotted into the net.
Wolves thought they had a penalty when Le Fondre looked to have been tripped by Steer, but referee Chris Kavanagh decided to book the Cardiff City loanee for a dive instead.
Joel Lynch brought a late save out of Martinez as Huddersfield tried to inspire a comeback, but Wanderers sealed victory with Afobe's second in the dying moments.