Los Angeles, July 18: Russian Igor Kunitsyn produced the biggest upset of the Los Angeles Classic with a 7-6 7-5 victory over fourth seed David Nalbandian in the opening round.
The 25-year-old from Vladivostok, playing the best tennis of his career, clinched the first set 7-5 on a tiebreak before holding off an inspired Nalbandian fightback.
''It is one of my best victories,'' a beaming Kunitsyn told reporters after wrapping up the match in just under two hours in sapping heat at the Los Angeles Tennis Center yesterday.
''I think I can say it is my second best win. My best win was when I beat (Lleyton) Hewitt in Adelaide in front of a full crowd,'' he added, referring to his three-set victory over the Australian in January.
''But this is the best tennis I have ever played.'' After winning the opening set, Kunitsyn raced into a 3-0 lead in the second before his Argentine opponent finally found his rhythm to reel off the next five games.
Nalbandian, runner-up to Hewitt at Wimbledon in 2002, served for the set at 5-4 and 40-30 but double-faulted.
Kunitsyn twice held advantage, first with a rasping backhand winner and then after Nalbandian hit a forehand long to set up one of the most controversial points of the match.
A protracted rally which seemed to go in Nalbandian's favour was replayed, following an overrule by the umpire, and another forehand error by the Argentine gave Kunitsyn the game to level the score at 5-5.
The Russian, 99th in the ATP rankings, held serve before breaking Nalbandian for the sixth time, a crunching forehand giving him match point at 30-40 before his opponent netted a backhand.
''Fortunately he gave me chances at 5-4 and then there was that call,'' said Kunitsyn, who has based himself in Sacramento, California for half of this year to train with compatriot Dmitry Tursunov.
''I don't know what happened there but he got a little bit frustrated and that actually helped me to break him at 6-5. It was a crazy match, it could go either way at any time.'' Sixth-seeded wildcard Mardy Fish ended an eight-match losing streak by beating his doubles partner and fellow American Sam Querrey 7-5 6-4.
''I'm definitely excited to win again and it's really good to be back in the States on true bouncing courts,'' Fish said. ''I wasn't planning on playing here but I wasn't planning on losing eight in a row either.'' In other matches, American Vince Spadea eased past Brazilian Thiago Alves 7-6 6-2 and Britain's Alex Bogdanovic retired with a back injury after losing his first set 6-1 to Czech Radek Stepanek.
Second-seeded American James Blake, hunting his first ATP title in six months, and top seed Fernando Gonzalez were scheduled to play later.