Novak Djokovic's former coach Boris Becker has criticised the Serbian for lacking fight and playing too defensively during his Australian Open defeat to Denis Istomin.
Becker and Djokovic split at the end of last year following a disappointing run of form for the 29-year-old, who failed to win Wimbledon, the Olympics or the US Open.
Djokovic also surrendered the world No.1 spot to Andy Murray.
The new season was supposed to represent a fresh start but Djokovic was beaten 7-6 (10-8) 5-7 2-6 7-6 (7-5) 6-4 by wildcard Istomin on Rod Laver Arena.
It is the first time he has lost before the third round of a grand slam in 34 attempts, since he bowed out at the same stage of Wimbledon in 2008.
"I'm really shocked that Novak Djokovic lost," said Becker, who is part of Eurosport's live coverage of the Australian Open.
"I thought he was playing much too defensive and never really took the initiative and never really fought for it.
"I absolutely never expected him to have trouble with Denis Istomin. No disrespect but Nole is a six-time Australian Open champion.
"But I could tell in the first set he was way too defensive and way too passive. The first set in a three out of five match is always very important.
"In the fourth set again he was a bit lethargic and not playing at full power.
"Then once you're in the fifth set anything can happen and credit to Denis, he kept his composure, he kept his nerve, he went a break up and kept serving well and hitting the lines so it's well deserved."
PA
