James Chester's second-half header was enough to earn the Tigers all three points at Loftus Road as QPR striker Charlie Austin saw an 84th-minute penalty saved by Allan McGregor.
Ferdinand was marking Chester as the Hull defender nodded home the winner but Redknapp had nothing but praise for his former Manchester United centre-half.
"Rio was excellent," Redknapp said of his highest-profile summer signing. "I thought it was an absolute master-class in how to play at the back.
"He looked so comfortable, his touch, his passing, his reading of the game - he's a fantastic footballer."
QPR enjoyed the better of the chances in the game, particularly in the first period, but a lack of cutting edge in the final third cost them dear.
The hosts could have rescued a point six minutes from time when Chester was adjudged to have handled Junior Hoilett's cross but McGregor palmed Austin's spot-kick to safety.
"Some days it just doesn't go your way," Redknapp said. "You get a penalty late on and I think if we'd scored the penalty we had time to win the game, the momentum was with us.
"Some days you get the breaks and some days you don't.
"I thought in the first half we played well - we had good control, a good shape to the team, we passed it well and created some good chances so it was encouraging."
QPR's greatest threat came from Loic Remy, who caused Hull problems with his pace and movement.
Remy came close to joining Liverpool earlier in the summer but failed a medical and Redknapp hopes the Frenchman now remains at the club beyond the transfer window.
"One or two clubs have enquired since Liverpool but they weren't clubs he'd want to leave QPR to go to I don't think," Redknapp said.
"Liverpool was a big move for him obviously with the Champions League and everything else so I think it'd have to be a Champions League-potential club for him to move."
Redknapp continued: "I hope he'll be here with us. We need to know pretty soon, I wouldn't want him to leave at the end of the window because that's going to be a big problem for us.
"If he's going to stay we need to get a commitment he's going to stay with us - I'd like him to stay, his attitude has been first class."