Miguel Angel Angulo put Valencia on course with a late first-half goal before substitute Fernando Morientes secured the win one minute after restart.

The win tightened Valencia's grip on Group D with 13 points, six ahead of second-placed Roma who lost 1-0 at Shakhtar Donetsk, while Olympiakos remain in last place with only two points.

Valencia suffered an early blow when star striker David Villa injured in the 22nd minute.

However, Angulo stepped up to steal the spotlight with a brilliant goal that saw him receive Curre Torres' pass inside the area before drilling the ball home past goalkeeper Nikopolidis.

The Spaniards doubled their lead through Morientes who towered to head home from David Silva's deft cross only seconds into the second-half.

Elsewhere, Italian outfit AS Roma suffered a stunning 1-0 defeat at Shakhtar who raised their tally to five points in third place.

Ciprian Marica scored Shakhtar's only goal one minute past the hour to keep the Ukrainians in contention for a knockout stage spot.