Cristiano Ronaldo's penalty has put Real Madrid on course for a La Liga victory over Valencia at the Mestalla and 23rd successive win in all competitions.
Manchester City loanee Alvaro Negredo was adjudged to have handled the ball inside the box on 14 minutes, and Ronaldo was never going to miss.
It was the Ballon d'Or favourite's 33rd goal in 25 club appearances this season and came via the first clear-cut chance of a somewhat scrappy opening.
The Portuguese should have perhaps doubled his tally and Madrid's cushion when he ran on to a through-ball from Gareth Bale and rounded Valencia stopper Diego Alves, only to shoot into the side-netting.
Valencia finished the half strongly and twice came close to an equaliser as Pepe produced a crucial block to deny Antonio Barragan, and Andre Gomes struck the post with an effort which had Iker Casillas beaten.
Table-topping Real would go four points clear, and 11 ahead of fifth-placed Valencia, with victory this evening.
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