Mackenzie McDonald and Tommy Paul gave the United States a 2-0 lead in their Davis Cup qualifier against Uzbekistan on Friday, winning their singles rubbers in straight sets in Tashkent.

Fresh off their Australian Open exploits, McDonald wasted little time in getting the U.S. - record 32-times Davis Cup winners - on the board in the indoor arena at the Olympic Tennis School.

Having claimed his biggest career win when he toppled Australian Open top seed Rafa Nadal in straight sets in the second round, McDonald beat Sergey Fomin 6-4 6-1 in little over an hour, sealing the match with an ace.

McDonald is one of three debutants for the American team in the Davis Cup alongside Denis Kudla and Austin Krajicek, with interim captain David Nainkin saying the tournament is a "huge priority".

Paul, who reached his maiden Grand Slam semi-final at Melbourne Park last week and moved up to a career-high 19th in the world, claimed a 6-1 7-6(6) victory over Khumoyun Sultanov who is ranked 461 rungs below the American.

Although Sultanov had his moments in the contest and won a couple of long rallies to earn the applause of the sparse crowd inside the arena, he was no match for Paul's power as the American sealed the opening set with an ace.

Sultanov looked set for a surprise comeback in the second set when he stormed into a 4-0 lead but Paul recovered quickly to tie the set at 4-4 before prevailing in the tiebreak, sealing the win with a forehand winner at the net.

The doubles rubber will be played on Saturday with Americans Rajeev Ram and Krajicek set to take on Fomin and Sanjar Ayziev, before the reverse singles matches.

With 24 nations competing in the qualifiers this weekend, the 12 winning teams will qualify for the Davis Cup Finals group stage in September alongside 2022 champions Canada and runners-up Australia while Spain and Italy both received wildcards.