Ryan played the full 90 minutes in the second leg, beaten by Louis Verstraete's 84th minute strike.

The Australian could do nothing to prevent the goal with Verstraete firing home from the penalty spot after Samuel Kalu's cutback.

Genk had earlier taken the lead through Timothy Castagne's angled strike after 20 minutes.

The Socceroo, who saved a penalty in the 5-2 first leg win, had little to do with Gent struggling to mount a challenge in the second leg.

Ryan's Genk will learn who they'll play in the quarter-finals at 11pm AEDT on Friday.

The clubs left in the draw are Manchester United, Schalke, Ajax Amsterdam, Besiktas, Anderlecht, Celta Vigo and Olympique Lyonnais.