“I felt he was diving before there was contact,” said Schwarzer of the 75th minute incident involving a Jonathon Woodgate tackle which sent an off-balance Ronaldo plummeting to the ground inside the six yard box.

Referee Mike Dean had no hesitation in pointing to the spot and the 22-year-old Portuguese wizard coolly slotted home. “It was a soft penalty,” added Schwarzer from China, where he’s preparing with the Australian team for a friendly against China on Saturday.

The converted spot-kick was enough to see the Red Devils through, but not before howls of protest from an infuriated Boro on the night.

Substitute James Morrison was dismissed for an bad foul on Ronaldo in added time and the United assistant manager Carlos Queiroz and his Boro counterpart Malcolm Crosby were involved in a heated verbal battle on the touchline after the final whistle.

“I seem to be only good at stopping penalties in shootouts,” joked Schwarzer, 34.

Despite many pundits saying Ronaldo is the best player in the Premiership, Schwarzer stopped short of a similar rap: “Ronaldo is very close to the best in the league. Perhaps he gets overshadowed by other things that happen though.”

However the Aussie glovesman, who pulled off a string of brilliant saves to deny United, said this was the year for Sir Alex’s side. “I think they can win it. Put it this way, it’s theirs to lose.”