Andy Murray was at his tenacious if not fluent best as he secured a place in the Montreal Masters semi final with a scrappy straight sets victory over Nikolay Davydenko.

The British number one, bidding to overtake Spain's Rafael Nadal as the world's number two in Montreal, claimed a 6-2, 6-4 victory but failed to reproduce the quality he displayed in seeing off Juan Carlos Ferrero in the previous round.

Murray will now face world number one Roger Federer or Jo-Wilfried Tsonga in the last four and will leapfrog Nadal should he win the tournament or reach the final and the Spaniard fail to do so.

The Scot was somewhat sluggish out of the blocks but dug deep to hold his first service game, before breaking the Russian, who blew hot and cold all afternoon.

But Murray handed the impetus straight back to Davydenko, double faulting when facing a break point, only to regain the momentum with another break.

And Murray stopped the rot by holding his serve, before comfortably serving out the first set.

The second set began in similar fashion to the first and Murray was continually and uncharacteristically off target with his ground strokes and his serve.

But with the scores at 4-4, a trademark running passing shot shook the Scot into life and, having forced Davydenko to serve to stay in the match, Murray smelled blood and sealed a rather unconvincing victory.

In Friday's late matches, world number four Novak Djokovic meets Wimbledon finalist Andy Roddick before Nadal continues his comeback from injury against Juan Martin Del Potro.