The Bianconeri were stunned by Manchester United in Turin during their last group game but sealed their place in the last 16 with one game to spare on Wednesday (AEDT).

In a game of few chances, Mandzukic scored a tap-in in the second half after Cristiano Ronaldo had worked space to steer a cross to the Croatian striker.

United's last-gasp win over Young Boys means Valencia can no longer reach the last 16 even if they beat Mourinho's side at home in their final group game.

Juventus had been awarded two penalties in the reverse fixture with Valencia but Miralem Pjanic, the scorer of both of those spot-kicks, was denied another in the first half when he claimed he was pulled back by Geoffrey Kondogbia.

The Bianconeri dominated possession but struggled to conjure up chances and Joao Cancelo's outside-of-the-foot effort that went wide was as close as they came to a first-half goal.

It was Valencia who almost took the lead on the stroke of half-time, but Wojciech Sczcesny's brilliant one-hand save repelled Mouctar Diakhaby's header from a corner.

Juventus continued to look short of ideas until Ronaldo's moment of magic just before the hour mark.

The Portugal forward's stepover fooled Gabriel and gave him enough space to steer across a ball that Mandzukic turned home from close range.

Valencia thought it had hit straight back when Diakhaby got a touch to Dani Parejo's near-post free-kick.

However, the ball had clearly struck the defender's outstretched arm and rather than being credited with an equaliser, Diakhaby was punished with a yellow card from referee Willie Collum.

Neto denied Paulo Dybala, Ronaldo and Mandzukic a second Juve goal, but Valencia never looked like getting an equaliser at the other end as they exited the competition.