The Murray serve kicked into top gear in the closing stages and, with the watching Federer and Rafael Nadal getting a taste of the atmosphere inside the arena, the Scot broke again with a backhand winner to secure an impressive win in two hours 10 minutes.

BBC: Andy Murray beats Del Potro in ATP Finals opener

To witness the back-and-forth of their flirtation is like watching Nadal versus Federer on clay.

NEWYORKER: Hot and Bothered

There was no sign of the drama to come when a relaxed-looking Federer, his parents Robbie and Lynette watching from the Royal Box, strolled out onto a sunny Centre Court, wearing a gold-trimmed zip-up cardigan.

BBC: Wimbledon 2010: Roger Federer survives massive scare