Seven-time grand slam champion Venus Williams made it through to her first Australian Open quarter-final in five years after trumping Pole Agnieszka Radwanska 6-3 2-6 6-1.

Williams - the 18th seed - had not made it past the third round at Melbourne Park in four previous attempts since losing her quarter-final match to Li Na in 2010.

But the 34-year-old, who had 43 winners to go with 36 unforced errors, ended that drought thanks to a three-set win against last year's semi-finalist after two hours and five minutes on Rod Laver Arena.

Next up for Williams is teenager Madison Keys in an all-American quarter-final.

Williams and Radwanska could not be separated in the opening set until a marathon 30-point seventh game that saw the former claim the break and a 4-3 lead.

The 34-year-old consolidated that break and wrapped up the opener on Radwanska's serve after four set-point opportunities.

Williams threatened to take a stranglehold of the match early in the second set, but Radwanska dug herself out of a 15-40 hole to hold serve in the second game.

And that proved to be the turning point for Radwanska, who sprung into action.

Aided by Williams' 20 unforced errors compared to her four, Radwanska broke twice en route to clinching the set and forcing a decider.

Radwanska maintained that momentum early in the final set, breaking serve in the opening game, only for Williams to break back immediately.

And Williams wrested the ascendency away from her opponent, going up a break in the fourth game.

Williams never let that lead slip, breaking again in the sixth game as she served out the match with a second-serve ace for a spot in the quarters.