Australia is yet to win a match in the Olympic tennis tournament after Bernard Tomic was the latest to be eliminated.
In a rain-interrupted match Tomic went down to 15th seed Kei Nishikori of Japan 7-6 (7-4), 7-6 (7-4).
It followed the day-one losses of Sam Stosur in the women's singles and doubles pairing Jarmila Gajdosova and Anastasia Rodionova.
In other day-two results at the Wimbledon Olympic tournament top seeds Jo-Wilfried Tsonga (France), Novak Djokovic (Serbia), David Ferrer (Spain) and home favourite Andy Murray were all winners in the men's singles.
Tournament number two seed Djokovic was made to work hard for his victory over Italian Fabio Fognini 6-7 (7-9), 6-2, 6-2. Tsonga also had to fight back from a set down before overcoming Brazilian Thomaz Bellucci 6-7 (5-7), 6-4, 6-4.
Murray, who gave a tearful speech at Wimbledon when losing the recent final to Rodger Federer, was well received in his return to the All England Club.
Soaking up the home support Murray accounted for Switzerland's Stanislas Wawrinka 6-3, 6-3.
"I'm really up for this tournament," Murray said.
"I want to be involved for as long as possible. I'm going to give it my best shot."
Men's fourth seed David Ferrer was also a comfortable first-round winner beating Canadian Vasek Pospisil 6-4, 6-4.
In the women's singles second seed Agnieszka Rdwanska of Poland was beaten by Julia Goerges of Belgium 7-5, 6-7 (5-7), 6-4 while third seed Maria Sharapova of Russia defeated Israel's Shahar Peer 6-2, 6-0.
Lleyton Hewitt, the only remaining Australian in the Olympic singles draw, will play his first-round match against Sergiy Stakhovsky of Ukraine at 8.30pm (AEST) on Monday.