Houston, USA, 11 April 2013 | AAP

An ailing Lleyton Hewitt paid a price for his Davis Cup loyalty as he fell to a first round defeat at the US Men’s Clay Court Championship.

Hewitt won the first set before being worn down by world No.94 Martin Alund of Argentina, who won 4-6 6-3 6-1.

Former world No.1 Hewitt had made the tiring trip from Uzbekistan after helping Australia to a 3-1 victory in their Davis Cup tie in Namangan.

“It’s tough to get back from there to play the next week,” Hewitt said.

“I just didn’t feel close to 100 per cent. It was a stomach thing. It’s frustrating. If I could have gotten through this match I could have felt better as the week goes on. It wasn’t to be.”

Hewitt broke Alund in the seventh game of the first set and closed out the set with an overhead winner.

Alund and Hewitt traded breaks in the second and third games of the second set before Alund took control.

Hewitt was broken again in the sixth game and Alund escaped two break points before capturing the second set in the ninth game.

The Australian escaped three match points in the final game but then double-faulted to end the match.