We looked to be heading out of the competition when trailing 2-0 early in the second half of the delayed fourth-round tie.
But bustling striker Doherty led the fightback as the patched-up team hit back to score four times and set up a home clash with Stockport.
The 21-year-old scored the late winner in the 1-0 third-round victory at Leyton Orient playing in central defence and, while he did not find the net at the Valley, he was named Spurs’ man of the match.
Doherty made his first full appearance this season in attack in the poor display at Ipswich, but was then shifted back to join Chris Perry and Sol Campbell to great effect.
"I still think he's a better back player," admitted George. "He played up front as an emergency tonight because we had no-one else.
"He has played ever so well at the back. He has come from a small club to a big one and shown great enthusiasm and this is a step up for him. He is very comfortable on the ball for a big lad and he is good in the air. He did fantastically for our first goal out of nothing.
"It was very important when he got to the byline and smashed one across the box which was turned in for an own goal. From then on we showed a lot of confidence and put passes together."
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George Graham paid tribute to occasional striker Gary Doherty for his part in keeping our FA Cup interest alive following the remarkable comeback against Charlton.