UPDATE 3.50pm: Australia’s Marinko Matosevic has been knocked out of the Brisbane International in a first round defeat by American Steve Johnson.
The world No.77 won the first set but crumbled in a second set tiebreak before going on to lose 2-6 7-6 (0) 7-5 to the world No.37.
Matosevic began brightly, winning the opening set in just over half an hour on Pat Rafter Arena.
But Johnson rallied and won the second-set tiebreaker 7-0 before wrapping up the third set in 51 minutes.
Johnson will face world No.5 and US Open finalist Kei Nishikori in his next match, with the Japanese star having a bye in the first round.
Earlier on Tuesday, fifth seed Kevin Anderson became the third seed to fall in the opening round when he was upset by Polish journeyman Lukasz Kubot.
The world No.16 South African was beaten 7-6 (7-3) 6-4 by the Polish qualifier to join French pair Gilles Simon and Julien Benneteau on the tournament scrapheap.
Kubot, the world No.177, will now play defending champion Lleyton Hewitt or Sam Groth in the second round.
Hewitt and his fellow Australian play later on Tuesday.