McDonald gave Rangers the lead for the first time in the tie with a towering header from a Matthew Brazier corner to earn them a home match against Barnsley in the fourth round.
Huddersfield had taken the lead after seven minutes in a move started in midfield by Lee Makel. He played a terrific long pass to Andy Payton on the left and he fed Rob Edwards, who advanced and beat Karl Ready before firing home. QPR equalised after 26 minutes when Gavin Peacock broke through a melee in the Town defence to beat Steve Francis.
Two goals in three minutes saw Barnsley through against Oldham at Oakwell. Martin Bullock scored Barnsley's first with a superb 25-yard strike in the 27th minute and three minutes later Bullock turned fed the Trinidadian international Clint Marcelle.
Carlisle, of the Third Division, pulled off a shock in one of the night's rearranged third round ties when they beat Tranmere Rovers 1-0 with a goal after 30 minutes by Owen Archdeacon from Lee Peacock's cross. Tranmere, chasing promotion to the Premiership, had their player-manager, John Aldridge, sent off 12 minutes from the end.
The freezing conditions wreaked havoc on fixtures in England last night. Thousands of furious Manchester City fans made a fruitless trip London when their FA Cup third-round tie at Brentford was called off just two hours before kick-off. To add to the chaos, Manchester City directors in London for the game only found out from the radio.
The club secretary, Bernard Halford, said: "No one informed us that the match was off. We heard it on the radio and apparently it was a late decision."
Mick Fletcher, the match referee, was driving from his Midlands home to Brentford unaware the pitch was freezing as temperatures plummeted. He admitted: "Brentford officials were apparently trying to contact me in the afternoon. I was on my way but I don't have a mobile telephone. I left my home at 3pm and apparently I was told the pitch was playable then.
"I didn't know anything about the pitch inspection until I got to the ground. It's up to the club to get in touch with me. At 5.30pm I had a look at the pitch and one side of it was badly affected by the frost. I appreciate the fans had travelled a long way but we have to take note of the weather conditions and players' safety is first on the agenda."
City fans were still outside the ground an hour after the match was called off, demanding an explanation of the situation.
In Kent, Gillingham's third-round tie against the Premiership club Derby County was abandoned after 66 goalless minutes because the pitch was freezing.
Watford's game against Oxford was called off just before kick-off, the pitch having deteriorated after a final inspection.Reuse content