Hair-raising: Andy Murray's Girlfriend and the Farrah Fawcett Look

Well, wasn't that a nailbiter? Not just the tennis – although Andy Murray's grinding five-set defeat of the 19th seed, Stanislas Wawrinka, did have its share of suspense and excitement.

Your sports correspondents will no doubt attend to those matters elsewhere.

It befalls us here, though, to address a question every bit as perplexing as what it takes to make Murray – just once – smile. Namely, his girlfriend Kim Sears's barnet.

Viewers of last night's BBC coverage of the Wimbledon fourth round match will have noted that the Corporation's camera folks, as well as cutting to repeated shots of Ian Hislop and/or girls in vests jiggling up and down, returned repeatedly to the seats in which Murray's mother and Kim were sitting side by side.

From this, we discovered that Judy Murray has a Braveheart yell every bit as ear-rending as that of her son, and that Sears has lovely hair.

Centre Court with the roof closed may have been, in Murray's words, "like a bath", but a little bit of crushing humidity wasn't going to have any affect on those tumbling curls.

Sears clapped decorously, her golden locks wafting like a Botticelli goddess. It takes many hours in curlers, and a lot of hairspray, to look that effortless.

We know that 21-year-old Sears is the daughter of Nigel Sears, the head coach of British women's tennis, that she is a student at Brighton university, and that she considers the secret of her four-year relationship with Murray to be "it's not about me, it's about Andy".

But the other pressing questions of the day – who is her hairdresser, and how many cans of Elnett does it take? – remain, so far, sadly unaddressed.

How moving, though, to see the nation's young people paying tribute to those who have gone before.

The spirit of Farrah Fawcett lives on, and you can see that look again when Murray plays Juan Carlos Ferrero for a spot in the semi-finals tomorrow.