Biggar needed treatment late in the game after going up to gather a high ball that won Saints a crucial penalty in the 25-18 success.
Harry Mallinder took over kicking duties and landed the kick before Saints stood tall in defence to make sure of the victory.
And attentions now turn to next weekend's home game against champions Saracens, with Wales fly-half Biggar shrugging off any injury fears ahead of that clash.
"It was just a bump, a bit of a sprain in my foot but I'm fine so I should be okay for next week," Biggar said.
And on the victory against Quins, Biggar, who switched to Saints from Ospreys during the summer, said: "Nights like this are a major reason why I signed here because week in, week out, this is what it's like here at the Gardens. It lived up to expectation.
"We should have been a bit further ahead at half-time but we played some good rugby at times and we got the win so all in all we've got to be pleased.
"We're on the board now and we can start looking up.
"It's as tough as it gets next week but it's a bit of confidence for the boys and we're really excited about the week coming up."