Real Madrid moved top of La Liga as Karim Benzema struck in each half to earn the visitors a 2-1 win over Athletic Bilbao at San Mames on Wednesday.

Cristiano Ronaldo went into the game one off 500 career goals and three away from becoming Madrid's all-time leading goalscorer ahead of Raul, but it was Benzema who made the difference - scoring either side of Sabin Merino's equaliser in a predictably difficult encounter for Rafael Benitez's men.

Benitez was without Sergio Ramos, Gareth Bale and James Rodriguez but a sloppy backpass from Mikel San Jose to goalkeeper Gorka Iraizoz allowed Benzema to open the scoring 19 minutes in against the run of play.

Benzema's fifth goal in as many appearances this season was cancelled out by Merino as Ernesto Valverde's hosts claimed a well-deserved equaliser seven minutes after the hour.

It was the first competitive goal conceded by Real under Benitez but Benzema was on hand again within three minutes to restore his side's lead as the visitors made the most of Barcelona's surprise defeat to Celta Vigo earlier in the night.

They go top of the table - level on points with Celta - having negotiated arguably the toughest test of the Spaniard's reign so far without a host of key players.

Athletic won the corresponding fixture last term courtesy of an Aritz Aduriz goal and the striker should have tested Keylor Navas early on but hesitated and allowed Raphael Varane to recover.

Benzema saw two efforts veer off target in the opening 15 minutes before being gifted the opener as Athletic undid all their early good work.

Iraizoz played the ball out to San Jose and, under pressure, the centre-back underhit his pass back, allowing the Frenchman to steal in and prod home the opener.

The hosts' goalkeeper was called on again to deny Ronaldo's dipping effort from distance as Madrid asserted control, Benzema next to threaten as he almost got on the end of Marcelo's cross.

Aduriz went close with a header at the other end, while Raul Garcia's strike was well blocked by Pepe before the break. Iraizoz was also kept busy, saving from Mateo Kovacic at close range.

Athletic were the brighter following the restart as Navas was tested by another Aduriz strike - the visitors struggling to create much attacking rhythm in the absence of Bale and Rodriguez.

Valverde's men continued to apply pressure and they gained their reward when Merino made the most of a quick break to convert Markel Susaeta's dangerous delivery with Madrid's defence stretched.

However, parity was shortlived as Athletic this time saw themselves cut open at the back, Isco the architect for Benzema's second.

The striker converted a crucial strike from close range with 20 minutes remaining, as Benitez's Madrid continue to show their gritty side.

Ronaldo's wait for further Bernabeu history, meanwhile, goes on.