Two lengthy rallies played to Murray 's strength , with a breathless Pospisil given a time warning at 30 - 30 .
The 2013 champion clinched the key break with a drop shot and a backhand .
Two lengthy rallies played to Murray 's strength , with a breathless Pospisil given a time warning at 30 - 30 , and the 2013 champion clinched the key break with a drop shot and a backhand .