Giggs struck in the 2-0 win.
On his goal, he told Sky Sports: "It wasn't spectacular first half, we had to dig in. Rafa's goal was the outstanding thing in the first half, it was an unbelievable strike and he deserves it because he's been brilliant all season.
"To go 2-0 up, it gave us that extra cushion. At 1-0 you just never know what could happen. Once we got that second goal we kept the ball well and it knocked the stuffing out of QPR. We ran out comfortable winners in the end."