Andy Murray has a 'wonderful opportunity' to win Australian Open, says Barry Cowan

Andy Murray has a "wonderful opportunity" to win the Australian Open, but Barry Cowan says "it's disrespectful on everyone else to say he's won it".

After Novak Djokovic fell victim to one of the greatest shocks in Grand Slam history to Uzbek wildcard Denis Istomin, the result has left Murray in pole position to claim his first title at Melbourne Park.

Murray is now odds-on for his maiden victory in Australia, but Cowan believes there is far too much quality left in the draw with multiple major winners Roger Federer, Rafael Nadal and Stan Wawrinka still in contention

Djokovic shocked by Istomin

Novak Djokovic stunned by Denis Istomin at Australian Open

Milos Raonic, Kei Nishikori, Grigor Dimitrov and young hopefuls Dominic Thiem and Alexander Zverev will also feel like they now have a chance of making their mark at a major tournament.

"In sport, when someone falls early, there's always a chance for someone else to take their chance and that's what will happen. There are enough great players that you absolutely cannot say that Murray will definitely reach the final," Cowan told Sky Sports.

"There is no doubt in my mind that Andy __can handle the pressure - everyone knows he __can handle the pressure. But just because you can handle pressure doesn't mean that he's going to get through.

"With the conditions the way they are, it will be interesting to see how it develop over the next three or four days. With the speed of the courts you're going to get more shocks. It becomes a less of a physical battle because you can get days like today where when you're hot, everything goes in - you hit winners. When the courts are slower, you have to hit three, four, five great shots to win a point and you have to do it over and over again.

"Obviously it's a big shock that Novak is out, but 'wow' it opens the draw up. Andy is absolutely the favourite because not only is he world number one, but his biggest rival to beat him is out, so you've got Murray ahead of the rest and then I think you've got a lot of players below him who could all say 'this could be my chance'."

Istomin, the 30-year-old journeyman, played the match of his life to hand the six-times champion only his second defeat in 41 matches at Melbourne Park since 2011 with a 7-6 (10-8) 5-7 2-6 7-6 (7-5) 6-4 second-round win on Rod Laver Arena.

Istomin knew he would have to play the best tennis of his life to have even a chance of victory and he produced it in a captivating arm-wrestle of a contest against the 12-times Grand Slam champion after four hours and 50 minutes.

"I don't think anyone in their wildest dreams could not have foreseen that could have happened. It's important to stress that Denis Istomin is not a player who is 117 in the world - he's a much better player than that," said Cowan.

Novak defends Istomin shocker

Novak Djokovic defends himself over loss to Denis Istomin at Australian Open

"He's only had one win against a Top 10 player in 33 meetings, so to play as well as he did and go toe-to-toe with Djokovic was amazing. He was braver and that was the key - he went for his shots.

"Novak was very cautious, but for him to lose a five-set match against someone of Istomin's ranking was a shock. Since losing to Jurgen Melzer at the French Open in 2010, he won 18 and only lost three and those three were against Stan Wawrinka, Rafael Nadal and Andy Murray.

"This is a huge shift in the psychology and mentality of Djokovic, and more importantly for the rest of the tennis tour. We were talking about this guy being almost unbeatable a year ago, and now people do feel that they can beat him - that's half the battle."

Second seed Djokovic had won all five of their previous meetings, giving up just one set, and had lost to a player ranked outside the top 100 only once since 2010.

After winning his maiden French Open to complete a sweep of major titles, Djokovic's form fell away in the second half of last season, prompting queries about his motivation leading into the new season.

Those queries looked to be put to bed after he opened his season with victory at the Qatar Open, having beaten world No 1 one and long-time rival Murray in the final, but Cowan claims his trip back home after winning in Doha before flying out to Melbourne for the opening Grand Slam proved costly in the end.

"I read an article which said that Djokovic went home after Doha and then flew out to Melbourne and arrived Wednesday and I thought 'that's a bit strange', but then I thought that wouldn't count against him. But now that he's lost, that preparation was not 100 per cent fully focused to being ready right from the word go and that's come back to haunt him.

"His self-belief is not as high as it was 12 months ago and I'm not so sure he's as physically strong as he was a year ago. He's just not at the same level as he was when he went into the French Open."

Check our game-by-game updates from Andy Murray's matches as he aims for his maiden Australian Open title by following our blog on skysports.com/tennis, our app for mobile devices and iPad or our Twitter account @skysportstennis.

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