Murray boosted by doubles victory
Murray is already out of the singles in Barcelona
Murray, beaten 6-4 6-4 by Mario Ancic on Tuesday, partnered Ross Hutchins to a 6-4 2-6 (10-3) win over Swedes Thomas Johansson and Robert Lindstedt.
They now face Kevin Ullyett and Jeff Coetzee for a place in the last eight.
Reigning singles champion Rafael Nadal began his title defence with a 6-4 6-2 defeat of Italian Potito Starace.
Nadal, who beat Roger Federer to win his fourth straight
Monte Carlo Masters title on Sunday, overcame Starace in 78 minutes with four breaks of serve. 
606: DEBATE If Murray is going to win a grand slam, i don’t think it will be on clay as it doesn’t suit his style Derroj
The world number two from Spain has now won 99 out of his last 100 clay matches since claiming his first Monte Carlo title in 2005.
He will now meet fellow Spaniard and regular doubles partner , who advanced after a tough battle with wild-card Alberto Martin - also from Spain.
Lopez recovered from the loss of the first set to prevail 3-6 6-2 6-4.
Elsewhere, second seed opened his bid for the title with a convincing win over Gabriel Trujillo Soler.
World number five Ferrer was in commanding form, dropping just two games in his 6-1 6-1, 50-minute encounter, and plays Ecuador’s Nicolas Lapentti next for a quarter-finals berth.