By Tim Hanlon
BARCELONA (Reuters) - Real Madrid need Cristiano Ronaldo to channel his frustration into producing his top form as they face Barcelona in a top-of-the-table 'Clasico' showdown on Sunday that could decide the title race.
The Portuguese has struck a moody figure in recent weeks as Real struggled to recapture the blistering form that allowed them to set a Spanish record of 22 successive wins before the winter break.
Barcelona have capitalised on recent stumbles by Real, who have won only one of their last three league games, and earlier this month climbed to the top of La Liga for the first time since November.
Just weeks after holding a four-point lead over Barca, Real now trail their bitter enemies by a point and Carlo Ancelotti's men cannot afford any more slip-ups if they want to win a record extending 33rd La Liga title.
Ronaldo will also be eager to upstage Lionel Messi when the league's top two strikers -- who have scored 62 goals between them -- face off in the highly anticipated clash.
When the duo headed off for their winter breaks in December, Ronaldo topped the standings with 25 goals while Messi had netted 15 times.
But following a remarkable few months, the Argentine is now in front with 32 to Ronaldo's 30.
Such is Ronaldo's competitive nature that he has looked exasperated during games that have not gone Real's way.
Ronaldo's irritation was clear for all to see last week when he was seen saying "how embarrassing" Real were to team mate Karim Benzema following their 4-3 defeat by Schalke in the Champions League.
While Real squeezed through to the Champions League quarter-finals thanks to an aggregate 5-4 win, they are unlikely to get a reprieve in La Liga if they are trumped by Barcelona, who are on a six-match winning streak in all competitions.
Barca swept aside the challenge of Manchester City to book a place in the last eight of the Champions League on Wednesday, but midfielder Andres Iniesta refused to tag his side as favourites for the Clasico clash.
"There have been Clasicos where everything has happened and it is not down to how the teams are playing beforehand," he told reporters. "I don't think Madrid are playing badly and this is an important game for us against a direct rival."