Second seeds Mahesh Bhupathi and Max Mirnyi suffered a shock straight sets defeat in the doubles competition of the Tennis Masters Cup at Houston, USA.

They lost to Gaston Etlis and Martin Rodriquez of Argentina 4-6, 4-6 in the first match of the Blue Group on Saturday.

The Tennis Masters Cup is the yearend championships conducted by the ATP, ITF and Grand Slam committee, featuring the top eight players and teams. For the first time, the world doubles championships is being held in conjunction with the singles tournament.

The players and teams are divided into two groups -- Red and Blue -- of four each. After a round robin league, the best two proceed to knockout semifinals.

The other two teams in the doubles Blue Group are Bahamas' Mark Knowles and Canadian Daniel Nestor and Australian duo of Wayne Arthurs and Paul Hanley.

The Red Group features top seeds Bob and Mike Bryans of the USA; Wimbledon and US Open champions Aussie Mark Woodbridge and Jonas Bjorkman of Sweden; the French pair of Michael Llodra and Fabrice Santoro; and Martin Damm and Cyril Suk of the Czech Republic.

The singles events begin Sunday.