Nacho Novo and Neil Alexander were the heroes as Rangers booked a place in the UEFA Cup final.
Novo kept his cool to convert the decisive spot-kick after Alexander had saved from Fabio Liverani and Christian Vieri had missed in a tense penalty shoot-out.
Rangers will now feature in their first European final since lifting the European Cup Winners' Cup back in 1972, when they face former Light Blues boss Dick Advocaat's Zenit St Petersburg in Manchester on May 14.
Cuellar has been linked with a move to St James' Park involving a swap deal with Alan Smith, who was at the Old Firm match last week.But Smith's agent said the player was there with Celtic fans Stephen Carr, Damien Duff and Shay Given: "Alan has no intention of leaving Newcastle United, he is happy at the club. "
"All this Rangers talk has come about because he was at a couple of their games.
"It was just a coincidence as Alan got tickets for the Old Firm game and he went with a few friends to experience a Rangers v Celtic game as he is a football fan."