A surprising slide in the rankings to 28th meant former world number two Radwanska entered this week as an unseeded player, but she showed her quality in a 6-3 7-5 victory over British hope Konta.
In a repeat of last year's final match-up, this time fourth seed Konta could not take control of the contest against Poland's former Wimbledon runner-up.
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Consolation for Konta came with the fact she completed the match without obvious physical problems, five days after being forced to retire from her Brisbane International quarter-final with Elina Svitolina due to injury.
She now heads for Melbourne and the Australian Open, where 12 months ago she reached the quarter-finals, while Radwanska stays in Sydney and faces American teenager CiCi Bellis next.
Radwanska said of her win, according to wtatennis.com: " I'm just so happy to play such a great match before the Australian Open.
"It was a top-10 level match with some ups and downs, breaks along the way. The conditions weren't easy, but I'm happy to win in two sets."
Slovakian Dominika Cibulkova won a second-round contest against Russian Elena Vesnina to reach the quarter-finals, coming through a 6-4 6-4 victor, with Czech Barbora Strycova and Australian Samantha Stosur also posting wins on Tuesday.
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