The United boss said: "Diego's been a bit of a hero because the fans recognise that he doesn't give in. He's shown that in all the games he's played and the perseverance has paid off in a big way because the fans will never forget him now for this."
The Anfield showdown was a stalemate until Liverpool keeper Jerzy Dudek dropped yet another terrible clanger - allowing Jamie Carragher's header to squirm through his legs and gifting Forlan the chance to roll home his first goal on 64 minutes.
Forlan then beat Pole Dudek at his near post with a thumping drive minutes later, and although Sami Hyypia's late strike set up a tense finale, United held on for a crucial victory.
Ferguson added on Sky Sports: "I think we said all last week that the breaks are starting to come our way.
"We showed great temperament and a good team spirit.
"It was important for us to get consistency. Even at West Ham we were a bit unlucky. There's a great urgency about our game and great commitment, we saw it in Basel on Tuesday and today against the best team in the country."