Murray claimed a four-set victory against the Spaniard and will now face Milos Raonic for a place in the quarter final, with odds of 9/2 available (Sportingbet free bets) that the recent Olympic gold medal winner claims victory.
The number three seed is on course to meet Roger Federer in the semi-finals and would go into the match as outsider considering that the Swiss is playing at a very high level in this tournament, with Fernando Verdasco comfortably beaten in the third round.
Federer will now be expected to advance into the quarter final at the expense of Mardy Fish and the Wimbledon champion is 12/5 (bet365 £200 free bets) to claim a sixth US Open title, although it has been four years since he won at Flushing Meadows.
Novak Djokovic is the favourite on the outright market and the Serbian has barely put a foot wrong in this tournament, something which means he has shortened to 5/4 to retain his crown of twelve months ago.
The 25-year-old has had three very routine wins to reach the fourth round and one would not expect Stanislas Wawrinka to pose too many problems, although Juan Martin del Potro could provide a few problems in the last eight.
The Argentine won this tournament in 2009 and is a best price 16/1 to claim a second Grand Slam success this coming weekend, with Andy Roddick lying in wait and ready to retire once he is beaten at the 2012 US Open.
It looks hard to see a winner from outside the first four in the betting, although David Ferrer beat Lleyton Hewitt in four sets to reach the fourth round and the Spaniard is now 50/1 to claim his first Grand Slam title.