Manchester United winger Cristiano Ronaldo has taken a swipe at former Arsenal goalkeeper Jens Lehmann.

Lehmann, now of Stuttgart, says Arsene Wenger's men had a secret formula for keeping Ron quiet.

And the German No1 insists his side will use it to boot the winger and Portugal out of Euro 2008 in tomorrow's quarter-final.

But United star Ronaldo hit back saying: "The reason he knows me is because I keep knocking goals past him.

"We know his and Germany's weak points too - and we are going to exploit them.

"This is a massive match. The team that plays better will win. I'm confident it'll be us."

Ronaldo netted a penalty in United's 2-1 win over Arsenal last season.