Just watching what I missed.
Having played mostly well for the first two sets, he failed to capitalise on any of his break points (bar one) and then threw in a loose service game in the pivotal stages of both sets (5-5 and 4-4).
But from the third onward he was absolutely supreme - for a player who has often been criticised for having no weapons, he was hitting some incredible winners from all over the court. His backhand was exceptional - which is interesting to me, as there's not a lot of players out there with reliable backhands.
Whole match can be viewed here: http://www.bbc.co.uk/sport/live/tennis/32631296
On a side note, BBC's coverage is - as always - excellent.