-Royal couple were there to watch Andy Murray beat Richard Gasquet
-The Duchess was wearing Temperley's £395 Moriah dress which is on sale
-Both Williams sisters in shock fourth round exit from tournament
-Crowds surge as temperatures soar to 33 degrees
By Lauren Paxman and Paul Harris
Never mind the Royal Wave... Kate, Duchess of Cambridge looks expectantly over at her husband as she raises her arms for the Mexican Wave on Centre Court
You couldn't really blame him for taking a curtain call.
The Duchess of Cambridge might have been queen of Centre Court but yesterday – for the moment at least – Andy Murray was king.
Having roared to victory in straight sets against Frenchman Richard Gasquet, he performed an extravagant bow towards Kate and William in the Royal Box.
Here's the Mexican One: The second in line to the throne gets in to the spirit of the occasion
Your Majesty: British number one Andy Murray bows to the Duke and Duchess of Cambridge following his victory over Richard Gasquet in their fourth round match at Wimbledon
In turn, they gave him their seal of approval with a pat on the back after the match, won in 100f heat on court, and told him: 'Well done.'
Murray said: 'If I'd known they were coming, I would have shaved. I was thinking to myself as I came off I was sweaty and very hairy. I said to them, "I'm sorry, I'm a bit sweaty". But it was very nice to get to meet them.'
The bow, he said, was 'just, yeah, sort of off the cuff. Didn't think too much about it'. He added: 'I was obviously very happy after the match. I think it was the right thing to do.'
The win earns Murray a quarter-final clash tomorrow with the Spaniard Feliciano Lopez.
Happy couple: The Duke and Duchess of Cambridge sat in the Royal Box on Centre Court at Wimbledon
Pretty layering: Kate followed Wimbledon's specification that players must wear white
William and Kate became the surprise stars of the Royal Box after weeks of speculation that they might attend before embarking on their tour of Canada tomorrow.
Centre Court was crammed to capacity, which equates to 15,000 bums on seats. But to widespread disappointment, none, alas, was Pippa Middleton's.
For although there were frantic rumours during the morning that Kate's little sister and former maid of honour would arrive with the royal party, Pippa-watch was stood down at 12.31pm when the celebrated rear failed to emerge from the police-escorted cavalcade.
Kate, a huge fan of the game, wore what looked to be a triple-decker tennis skirt – in fact a £795 Alice Temperley dress – teamed with LK Bennett nude court shoes.
Within half an hour of her appearance, the frock, reduced to £395 in the summer sale, had sold out on the designer's website.
Unusual detailing: The white disks on Kate's shoulders will remind Wimbledon fans of a less successful recent fashion statement... Bethanie Mattek-Sands' Lady Gaga-esque jacket which was covered in white tennis balls
The royal spectators clapped and cheered as Murray got to grips with the heat. Later, during Rafael Nadal's match, they would even join in a Mexican wave.
Murray's triumph was followed by despair from the Williams sisters who made a shock exit from the tournament in the fourth round.
Venus Williams' attempt to win a sixth Wimbledon title ended in the fourth round with a 6-2, 6-3 loss to Tsvetana Pironkova of Bulgaria.
The 23-year-old Pironkova beat Williams at Wimbledon last year by the same score to reach her first Grand Slam semifinal. She also won their first-round match at the Australian Open in 2006.
Williams' defeat came shortly after younger sister Serena also went out in the fourth round, losing to Marion Bartoli.
It is the first time since 2006 that neither sister has reached the Wimbledon quarterfinals.
Expert in action: Andy Murray drew in a very A-list crowd for his match on Centre Court today
Fan club: Murray's girlfriend Kim Sears and his mum, Judy, were watching his progress
Support from afar: Andy Murray's tennis racket bag is covered with tweets from his fans
Kate and William appeared happy and relaxed as they watched the day's tennis. The Duchess has been a Wimbledon fan for years - as have all the Middletons.
Pippa has attended the French Open and the Aegon Championships since her big sister's wedding earlier this year and Kate has visited the championships twice before.
In 2007 she attended with a friend to watch Rafael Nadal play Swede Robin Soderling on Court one and in 2008 she visited again.
A polite thank you letter Kate wrote to Wimbledon bosses after her most recent visit is currently on display at the All England Club.
Keen spectator: This is Kate's third time at Wimbledon and her passion for tennis was clear to see from her facial expressions
Fun day out:William and Kate's visit to SW19 is a private affair and the newlyweds will not fulfil any royal duties
More than 2,000 people queued along the grassy banks outside the club in a bid to secure places for Murray's match.
As the fans waited outside, though, The Duke and Duchess of Cambridge took up their prime positions on Centre Court.
There they watched a very convincing display by Britain's number one who won the first set in a tie-break, soon claimed the second too and broke early in the third set.
As well as the young royals, Murray had his slightly more personal fan club in attendance.
His pretty girlfriend Kim Sears, and his mother, Judy Murray were sitting side-by-side at his fourth round match.
Murray's support also came from further afar, his tennis racket bag was covered with tweets from his legion of fans including 'stay positive we are all behind you' and 'believe in yourself and never give up.'
The perfect guest: Kate chatted and joked with Gill Brooke, the wife of the Chairman of the All England Tennis Club who was sitting by her side
Top tips: Kate leant back to give Jane Henman, Tim's mum, who was sitting behind her, a kiss on the cheek before exchanging a few words with her too
Kate and William's visit to SW19 is a private affair and the newlyweds will not fulfill any royal duties. But they both appeared very contented to chat to the others sitting around them.
Kate looked as composed as we have come to expect from the unflappable Duchess. She chatted and joked with Gill Brooke, the wife of the Chairman of the All England Tennis Club who was sitting by her side.
The relaxed tennis fan also leant back to give Jane Henman, the mother of our last big British hopeful, Tim Henman, who was sitting behind her, a kiss on the cheek before exchanging a few words with her too.
As the Royal Box guests arrived today, thousands of sun drenched fans applauded. But the heartiest welcome was reserved for the young couple who were given a standing ovation.
The retractable roof was also partially covered to shade the royals' end of the arena.
Other Wimbledon-goers were not quite as lucky, they used umbrellas to shade themselves from the sweltering sun as they sat on other courts or watched the action on Murray Mount.
Sizzling: Fans queueing to enter the grounds at Wimbledon struggle with the heat, with one man needing to lie down and another woman using an umbrella to shelter from the sun
Soaking up the rays: With a large bottle of water by her side, this woman lies on the tarmac and covers her forehead outside Wimbledon
Defeat: Serena Williams survived three match points. But ultimately crashed out against Bartoli in the tournament's first big upset