Just how good was Andy Murray yesterday in his straight-sets demolition of Stanislas Wawrinka in the quarter-finals?

I would have to rate it as perhaps his most complete performance in a grand slam. He has played three very good sets before, but more often from a point in the match when he was a set or two down. This time he was on it right from the off and determined to put on a show. To produce that consistently excellent standard of tennis all the way through was an emphatic statement of intent, the focus was great right from the start, the intensity outstanding and he was hitting the ball so cleanly. He can find the first two of three rounds of a tournament a bit of torture, but this was a whole different ball game and don’t forget Wawrinka was seeded ten himself, so far from an easy opponent.

There is a little bit of bad blood between Murray and tonight’s quarter-final opponent, Juan Martin Del Potro, how do you think that will impact the match?

Many of the foreign journalists have asked me about this, so they are obviously intent on writing about it, but I think more is being made of it than actually happened. It was in Rome this year when Del Potro made a reference along the lines of that nothing had changed from their junior days when Judy [Murray’s mother] was vocal in her encouragement of her son. Andy felt he [Del Potro] had insulted Judy and it certainly adds another dimension to this fascinating match. Del Potro is on this amazing run and it’s incredible to think that since Wimbledon he hasn’t lost a match. To win four tournaments in a row at any level is astounding, to win four in this kind of company is truly staggering, although there are signs that he is starting to feel the pressure of having won 23 matches in a row. Remember, all good runs come to an end.

What do you think Novak Djokovic [the No 3 seed] will be thinking after being taken to five sets by Tommy Robredo?

Robredo came into this tournament without any great form, he has barely figured in grand-slam events this year. But he beat Safin and has a couple of good wins under his belt and his confidence has soared. It required all of Djokovic’s strength of character and resolve to win. At times you got the impression that he was absolutely out on his feet. He would go down on his haunches and look as though he was all in, then in the next moment he would be prancing around like Bambi. I just think he’s very, very clever.

Elena Dementieva appeared to be untroubled in her game with Patty Schnyder [the Olympic gold medallist won 6-2, 6-3 to reach the semi-finals]. Why is she in this rich vein of form at present – what has changed?

I’ve had a sneaking feeling for her all tournament. She’s looking solid and striking the ball so hard. Patty Schnyder’s good, but not that good any more. Dementieva’s critics in the past would say that her serve was fragile, even embarrassing, and she was in danger of becoming the second [Anna] Kournikova because of the number of double faults she served up in all shapes and sizes. Her serve is now actually a weapon rather than an embarrassment and it makes a hell of a difference. In the women’s game if you serve well you’ve always got every chance.

And what about Roger Federer, he had to dig even deeper to beat Igor Andreev having also been taken the distance.

Everybody is having a tough time here – Nadal dropped a set, Djokovic dropped two and so did Federer. This tournament is taking its toll and with the Olympics coming just before it has placed a different burden on the players and it is clear that everyone is feeling it. It really is survival of the fittest out there, even more so this year. Roger had to save so many break points in the second set, it might have been so different had he dropped his serve and he may well not have come back from two sets down. But he survived and clung on and, as I keep saying, the best players in the world play the big points the best.

On another note, Jamie Murray and Liezel Huber have beaten Jill Craybas and Eric Butorac, the American pair, in straight sets, 6-3, 6-4, to reach the final of the mixed doubles where they will play Cara Black and Leander Paes, the No 5 seeds. Well done to them, it’s a fantastic achievement. Jamie must be the top-ranked mixed doubles player out there at the moment.

Neil Harman was talking to Richard Neale