Cristiano Ronaldo netted twice as Manchester United came from behind to beat ten man Tottenham 3-1 in the fourth round of the FA Cup.

The dismissal of Michael Dawson proved crucial - it was the Spurs defender's hand ball in the penalty area 21 minutes from time that led to United taking the lead as Ronaldo netted from the resulting spot kick.

Robbie Keane had put Spurs in front mid-way through the first-half but Carlos Tevez restored parity before the break.

Ronaldo then sealed the win two minutes before the end as Radek Cerny let the winger's low drive slip under his body for a soft third.

At 1-1, Spurs had chances to get back in front, but then Dawson let Wayne Rooney slip in behind him after a booming clearance from Edwin Van der Sar.

Rooney took the ball down superbly but just before he could shoot, Dawson's hand came out to bat the ball away. Referee Peter Walton spotted the infringement, sent the centre-half off, and then Ronaldo calmly put the spot kick away.

Tottenham took the lead with a finely crafted goal in the 24th minute. Aaron Lennon did superbly to trick his way past Patrice Evra and then he side footed home a low cross across the six-yard area. Keane was then there to tap in after superbly peeling off Rio Ferdinand, although Sir Alex Ferguson will be furious with his team's marking for the goal.

United were level seven minutes from time when Dawson could only head Rooney's long ball up into the air. Ryan Giggs then shielded the ball from Lee Young-pyo and Tevez was able to rush in and sweep home.

United had most of the play in the opening period but struggled to created anything and it was actually Spurs who had the better chances, with Rooney having to head off the line after a Dimitar Berbatov header early on and then, just before the break, Jenas broke away from midfield and Edwin Van der Sar had to get down quickly to make an excellent save.

After the break Jenas again broke free but this time scuffed his attempt and at the other end Ronaldo fired into the side-netting after he finally got in behind the previously outstanding Jamie O'Hara.

However, the Portuguese would have his moments before the end as he slotted home the penalty and then helped himself to a fortuitous second before the end.

Spurs were unlucky not to get anything from the game though, and indeed nearly levelled at 2-2 five minutes from time when Wes Brown deflected a cross onto his own post while under pressure from Berbatov.

Seán Fay / Eurosport