Radwanska was too precise for Li, completing a 6-3 6-4 win at Sydney Olympic Park.
It has been a scintillating run in the new season for Radwanska, who took out the Auckland tournament last week.
She's now won eight matches in a row and outside of Serena Williams is starting to look like one of the next line of players capable of winning the Australian Open.
It all looked fairly elementary for the 2012 Wimbledon runner-up until things tightened late in the second set.
Li, no stranger to a comeback after winning the 2011 Sydney International in straight sets after finding herself down 5-0 in the first set against Kim Clijsters, threatened to push the match into a decider.
After having her opportunities midway through the second set Li fought her way back from a break down when Radwanska served for the match.
Down 5-4 but on serve, Li saved seven match points across the two games but was ultimately broken straight back to lose the match.
The top seed and world No.4 Radwanska will play the winner of the Dominika Cibulkova-Angelique Kerber match next up on court.