Smith rolled back the years on Saturday as he helped the League One club batter Harry Redknapp's Premier League strugglers.
He admitted: "It's one of the best results in my career and will be remembered as fondly as those I had for Leeds. Obviously it wasn't as spectacular as who I was playing against - they were all European giants.
"But QPR are a Premier League team who have spent a lot of money. There are international players there."