Celtic drew 1-1 with Shakhtar Donetsk in Wednesday's Champions League Group F tie in Warsaw.
A 10th-minute own goal gave Ange Postecoglou's side an early lead in the Polish capital but the Ukrainian team equalised before the break.
In Group A, Rangers went down 3-0 to Napoli at Ibrox with all the goals coming in the second half after James Sands was sent off.
Next up for Celtic is a home game against Leipzig while Rangers face Liverpool at Anfield on matchday three.
