NEW YORK (AFP) — On a day when the stifling New York summer heat again had players reaching for their ice-packs at the US Open, hopes of a first US men's Grand Slam champion in seven years were set back with the defeat of Andy Roddick.

Roddick was the last US winner in 2003, the year before Roger Federer began his five-year reign, and, after a summer ruined by a bout of glandular fever, he looked back to his pumped-up best after taking the first set off dangerous Serb Janko Tipsarevic.

But the world No. 44, who was out for three weeks recently with injuries to both ankles, took command of a second set tie-break and with Roddick upset by a series of foot faults, the Serb went on to win the second round tie 3-6, 7-5, 6-3, 7-6 (7/4).

In the third round he will meet French showman Gael Monfils.

US hopes were kept alive, however, with wins for twin giants Sam Querrey and John Isner and the expectations are high that they are both capable of progressing deep into the tournament.

Tipsarevic said of his upset win: ''I was playing well, serving well, just had to find my momentum in the right games.

Off to a winning start in his opener was British fourth seed Andy Murray, who eased past Slovakia's Lukas Lacko 6-3, 6-2, 6-2.

Murray, seen by many as the main threat to tournament favourite Federer, agreed that his late start to the tournament, which leaves him needing to play seven matches in 12 days was not ideal.

The biggest casualty of the day in men's first round action was seventh seed Thomas Berdych of the Czech Republic, who was soundly beaten 7-6 (7/3), 6-4, 6-4 by the by the net-charging Michael Llodra of France.

Women's second round action saw straight wins over 19-year-old qualifiers for defending champion and second seed Kim Clijsters and for third seed Venus Williams.

The popular Belgian saw off Australian Sally Peers 6-3, 6-1, while Williams was made to dig deep by Rebecca Marino of Canada before pulling through 7-6 (7/3), 6-3.

Clijsters said that although she had conceded just nine games in her first two matches, she still needed to play better to have any hope of winning a third US title.

Also through was French Open champion Francesca Schiavone, who looked back to near her best in a 6-2, 6-2 demolition of Spain's Maria Elena Camerin.