MELBOURNE, Australia - An imperious No.8 seed Petra Kvitova turned up the heat against No.15 seed Ashleigh Barty in today's second Australian Open quarterfinal, powering into the last four of a major for the first time in nearly five years 6-1, 6-4 in one hour and eight minutes.

The result ensures that Simona Halep will be deposed as World No.1 next week: Kvitova has now overtaken the Romanian's points total, while Naomi Osaka, Elina Svitolina and Karolina Pliskova all also have a mathematical shot at overtaking her.

The Czech has won a Tour-leading six titles over the past 12 months, including in Sydney two weeks ago - where she edged Barty in a classic 1-6, 7-5, 7-6(3) final. However, having reached five Grand Slam semifinals or better in a five-year span between Wimbledon 2010 and Wimbledon 2014 - including one previous appearance in Melbourne in 2012 - she had failed to progress to that stage in the five years since capturing her second major title at The Championships in 2014.

Kvitova ended that drought in style today, roaring out of the gates with a purple patch of varied, free-flowing ballstriking that ensured a much quicker win than the Sydney epic. A bombardment of backhands blasted past the Australian - 25 winners would come off the 28-year-old's racquet today - with that heady brew leavened by the subtle touch of three judiciously timed, carefully placed dropshots.

The former World No.2 was also clutch in two crucial mini-battles, breaking Barty in the second game on her third opportunity with a backhand return aimed squarely at her opponent's feet - and then, having dug herself a hole in the next game with a double fault, patiently constructing a rally that she ended with a clever forehand angle to save break point before holding for 3-0. Thereafter, Kvitova accelerated towards the end of the set, breaking the crowd favorite again to love in the sixth game.

Barty, attempting to become the first Australian semifinalist here since Wendy Turnbull in 1984, drew on the fullest range of her extensive repertoire in a bid to halt the deluge of Kvitova winners. Over the course of the second set, the Zhuhai Elite Trophy champion brought out slices, clever geometric patterns to get her opponent on the run, deft net play and even a rare double-fisted backhand return winner. Barty also raised the efficacy of her serve, mixing up its direction more - and this paid off, with the 22-year-old conceding just four points in her first four service games of the set.

Instead, for the majority of the set it was Kvitova under pressure. The 26-time WTA titlist was forced to save a break point in each of her first two service games - but once again was rock solid to stave off a potential turning point, hammering down an ace to save the first and a booming wide serve to save the second, closing out both games with yet more backhand rockets beyond Barty's reach.

Forced to go for more and more just to cling on, Barty's higher-risk tactics frequently ended in error for the first-time major quarterfinalist: a lob that dropped just long, aggressive finishing shots that missed their mark. Moreover, Kvitova was adjusting to the variety, displaying superb reflexes and reach at net to survive being dragged into the forecourt by a Barty dropshot.

With the score level at 4-4, the two-time Wimbledon champion pounced, upping the ante on her backhand to put pressure on her rival's serve. Barty, struggling to keep up with the pace, dropped serve thanks to two errant forehands - and Kvitova would serve out to 30, sealing victory with a smash and an unreturnable serve to notch up her second Australian Open semifinal and first in seven years.