Zvonareva moves into semis

The Russian bullied the 20-year-old's serve with a fierce display of clean hitting from the baseline then weathered a late fight-back to close out the match in 75 minutes.

"She's (had) a great run here," Zvonareva said in a courtside interview of Kvitova, who knocked off seeds in her path to the quarter-finals but struggled to find her line against the Russian.

"I was just trying to hang in there and fight for every point, just try to stay aggressive and that's about it."

The world number two mowed through the first set in 29 minutes and marched to a 3-0 lead in the second before Wimbledon semi-finalist Kvitova snapped out of her stupor under leaden skies at Rod Laver Arena.

The sound of booming cannons fired as part of celebrations for the country's national holiday on Wednesday challenged the players' concentration, while what appeared to be an elderly spectator collapsing held up play for a couple of minutes.

Kvitova seemed to recover quickest from the distractions, breaking Zvonareva at 3-3 after a fierce baseline battle that ended with the Russian poking a forehand into the net.

"It was a bit of a difficult moment there ... It was a little bit distracting," said Zvonareva, finalist at Wimbledon and the US Open last year.

However, the 26-year-old held her nerve to break straight back then benefited from a net cord deflection at 5-4 that stopped the ball dead on Kvitova's side.

Kvitova, serving to stay in the match, scrambled forward to keep the ball in play, but Zvonareva calmly lobbed her to bring up match point and pumped her fists in celebration when the tiring Czech clubbed a forehand long to surrender.

Zvonareva will now play the Kim Clijsters, who beat Agnieszka Radwanska 6-3 7-6(4), for a place in the final.