Andy Murray admitted his aggressive style led to him playing "silly tennis" as he joined fellow Briton Tim Henman by exiting the Australian Open in the first round.
Murray was beaten in straight sets by Argentinian Juan Ignacio Chela after producing a performance way below expectation following his rapid rise last year.
The 18-year-old Scot suffered a 6-1, 6-3, 6-3 defeat by Chela at the Vodafone Arena before insisting pressure from the media was affecting his game.
"It's a little bit disappointing," he said. "I played really silly tennis for two sets. I played better in the third. I was just trying to be way too aggressive.
"I was making so many mistakes. That's just not the way that I play.
"When I did start to play my game, I had a lot of chances in the third set to break him. I didn't take them. I'm disappointed that I lost so easily. But I think I was due a bad match.
"Unfortunately, it came here."
Murray's defeat came a day after British No 1 Henman - the only other UK representative with Greg Rusedski opting to stay at home for the birth of his child- fell to Dmitry Tursunov.
Murray admitted he is feeling the pressure after playing his way into the spotlight.
"If you guys [the media] expect me to play well every single match and every single tournament then it's not going to happen," a flat Murray said.
"But I'm going to have much better days than this one, and I'm sure I'll have worse days. You guys [the media] are expecting me to win matches like this. The guy's ranked 20 places in front of me, he is a much better player than me."
Murray, 62nd in the world to Chela's 51st, continued: "It's difficult for me to go out there and try to perform to the best that I can when I'm expected to win all these matches."
After making the biggest jump of any player in 2005 as he surged from world No 514 to 65 by the end of the year - and also becoming the first British teen since Buster Mot-tram in 1974 to finish in the top 100 - Murray has been touted as a future champion.
But Murray had no answer to the consistent play of his more experienced opponent.
There were no such worries for top seed Roger Federer who cruised past the challenge of Uzbekistan's Denis Istomin 6-1, 6-3, 6-3.
There looked to be a major shock on the cards when Australian Lleyton Hewitt fell two sets to one down and a break down in the fourth set against Czech Robin Vik, but he recovered to edge through 6-4, 2-6, 5-7, 7-6 (7/4), 6-3 in nearly four hours.
"I was really struggling to get myself up," said Hewitt. "It was more a mental battle in the end to keep telling myself to hang in there and wait for the opportunity."
Fifth-seeded Russian Nikolay Davydenko ousted Croatian big server Ivo Karlovic in five sets, while sixth seed Guillermo Coria of Argentina also survived after being taken all the way by Romanian Victor Hanescu.
Chile's ninth seed Fernando Gonzalez became the highest-ranked casualty to exit the men's singles as American Alex Bogolomov Jr claimed his scalp in four sets, while Murray was in good company as he crashed out.
It was a bad day for France's new generation, with brilliant 19-year-olds Gael Monfils and Richard Gasquet hurried out after straight-sets losses to Peruvian Luis Horna and Germany's Tommy Haas, respectively.
There was some French success though, 25th seed Sebastien Grosjean easing past home hope Mark Philip-poussis 6-4, 6-2, 6-3.
German Nicolas Kiefer ended the hopes of former top-ten player Paradorn Srichaphan, justifying his 21st seeding by recovering from two sets down to win 6-2 in the fifth.