Striker Fernando Morientes scored twice to help Real Madrid beat Sparta Prague 3-2 in their opening Group C second stage match last night.

After a slow start Real showed their class, and went ahead through Zinedine Zidane's 20th-minute strike.

Rastislav Michalik equalised 10 minutes later to bring the home crowd to its feet, but Morientes made it 2-1 to Real in the 36th minute following a clever centre from Michel Selgado.

Though Real enjoyed most of the possession, Sparta Prague continued to threaten and in the 72nd minute midfielder Libor Sionko's long drive deflected off defender Francisco Pavon and past a helpless Iker Casillas to level the scores again.

But less than a minute later, Morientes picked up a rebound from Roberto Carlos' saved shot and slotted the ball home for the winner.

In the same group, Porto's defence held firm to frustrate Panathinaikos and earn a 0-0 draw.

The hosts dominated throughout with the powerful Michalis Konstantinou a constant threat.

But the Portuguese, marshalled at the back by Jorge Andrade and Ricardo Cavalho, didn't put a foot wrong under relentless pressure.

Konstantinou fired a header wide after six minutes and strike partner Emmanuel Olisadebe should have done better from close range minutes later.

The Nigerian-born Pole drove a right foot effort onto the upright just short of the hour but it was as close as Panathinaikos would come to a breakthrough.