The world number 37, who beat former US Open champion Sloane Stephens in the first round, lost 6-2 7-6 (7-2).

Tomljanovic lost to Konta at last year's event but this time led 4-0 in the second set before the British number one fought back.

Konta broke to lead 6-5 but her opponent broke straight back to force the tie-break, which she swept through.

Earlier, British number four Harriet Dart lost 6-2 6-0 to Latvian world number 11 Anastasija Sevastova.

Meanwhile, at the Shenzhen Open in China, Maria Sharapova consoled her Chinese opponent Wang Xinyu after she was forced to retire during their match.

Wang won two Grand Slam doubles titles in 2018

Wang, the youngest player in the tournament at 17 years old, led 6-7 (4-7) 5-2 when she was forced to pull out and she sat on her chair receiving medical attention with a bandage on her left thigh.

Five-time Grand Slam winner and fifth seed Sharapova went over to comfort the wildcard, chatting at length and saying "you played unbelievable".