Dirk Kuyt thought he had given his troops a 1-0 first-leg lead to take back to Stamford Bridge, having slotted from close range on 43 minutes at Anfield.
His goal came after Frank Lampard dithered in defence, allowing Javier Mascherano’s mis-hit shot loop into the path of Kuyt, who kept his cool to beat Petr Cech.
The Reds have proved to be Chelsea’s nemeses in this competition, having ended their bid at the last-four stage twice before in recent seasons.
And it looked like it was going to be their night once again.
But sub Salomon Kalou’s late cross into the Reds’ 18-yard box was headed into his own net by Riise, meaning the battle to reach this season’s final in Moscow is wide open.