Kiwi Michael Venus and South African doubles partner Raven Klaasen have blown an early lead to be knocked out in the second round of the Cincinnati Masters.

Fifth seeds Lukasz Kubot and Marcelo Melo have avenged their second round defeat by Venus and Klaasen last week in Toronto, to win 6-4 7-6 (4) in 1 hour 22.

Venus and Klaasen made a great start, striking first in the fourth game by breaking Melo's serve to open up a 3-1 lead. But then it started to unravel for the Wimbledon finalists with first Venus and then Klaasen dropping service games as the momentum swung in favour of the Pole and Spaniard.

Melo closed out the opening set with a comfortable hold in 32 minutes. Venus and Klaasen have been serving particularly well in recent weeks but today they were poor, managing only a 50 percent first serve ratio in the first set.


They were better in the second serve as games went with serve until the 11th game when Venus was broken. Showing their resilience the Kiwi and South African broke back to stay in the match and force a tie break but Kubot and Melo were able to close the match out.

The defeat will cost Venus ranking points as he made the semi-finals in Cincinnati last year and he could drop from his current position of 17 to around 20 by the end of the tournament. Venus and Klaasen remain 5th in the race for a spot at the ATP Tour finals in London but will need a good showing at their next tournament, the US Open which starts in just over a week, to enhance their prospects.