Tim Henman lost his rain-delayed opening match against world number two Andy Roddick at the Masters Cup in Houston.
The British number one played his part in a high-quality match but found home favourite Roddick too strong.
It is not the end of the tournament for Henman, who will face Guillermo Coria and Marat Safin in the round-robin format.
He can still qualify as one of the top two in his group and play in Saturday’s knockout semi-finals.
It would be a big surprise if Roddick, backed by a partisan crowd at the Westside club as he defeated Henman 7-5 7-6 (8/6), fails to reach the last four on this form.
It was a frustrating start to the event for both players, as the match was delayed for an hour and a half by persistent drizzle.
Henman was looking to improve his impressive 3-1 record against Roddick, but found himself in trouble at 0-30 when serving to stay in the first set in the 10th game.
He averted a crisis, helped by a fine backhand volley and equally impressive forehand pass.
Henman was not able to repeat the escape two games later, however, and 22-year-old Roddick broke to take the set 7-5.
The second set was even more closely contested and needed a tiebreaker to settle it.
Henman saved one match point but Roddick clinched the tiebreaker 8/6 and the match when Henman sent a forehand long.
Russian Safin beat Argentine Coria 6-1 6-4 in the first match in the group.