The Dane hadn't featured for Arsenal in two years.
He said: "Very emotional return, but what better way than with a win! Fans was absolutely incredible throughout the game and help us in difficult periods.
"For myself I was very moved by my reception and hearing my song again made my heart skip! Young players did ever so well and kept there cool in a difficult penalty shootout. Respect! Skipper looking fresh! (referring to Vermaelen)."