Agnieszka Radwanska breezed into the semi-finals of the China Open as Madison Keys took another step towards WTA Tour Finals qualification by coming through a marathon with Petra Kvitova.

Third seed Radwanska needed just an hour and 13 minutes to see off Yaroslava Shvedova 6-1 6-2, the Kazakh unable to offer much resistance in her second match of the day having earlier beaten Alize Cornet 6-2 6-4 in the third round.

Keys, seeded eighth for the tournament in Beijing, was provided with a much sterner test from two-time Wimbledon champion Kvitova, winning in three sets after two hours and 41 minutes.

The American will now face Johanna Konta, who boosted her hopes of a place in the Finals in Singapore by recovering from a slow start to end home hopes with a 6-4 6-0 win over Zhang Shuai.

Meanwhile, Elina Svitolina set up a meeting with Radwanska as she knocked out Daria Gavrilova 7-6 (7-3) 6-1.

SHVEDOVA UNABLE TO DO THE DOUBLE

It was always going to be a tall order for Shvedova to win two matches in the same day and so it proved as Radwanska condemned her to a heavy defeat.

Shvedova was shaky on serve throughout the march, allowing Radwanska to break her six times in an easy win.

And Radwanska can afford to be confident of progressing through to the final having won all three of her previous encounters with Svitolina.

KEYS OUTLASTS KVITOVA

Keys appeared set for a relatively routine win against a quality opponent in Kvitova when she led by a set and a break, only for Kvitova to fight back and force a tie-break despite dropping serve twice more in the second set.

The Czech subsequently won the shoot-out and demonstrated further resiliency by coming from 3-0 down to send the decider to a tie-break.

But Keys, eighth in the Road to Singapore standings, prevented Kvitova from completing the turnaround to win 6-3 6-7 (2-7) 7-6 (7-5).

KONTA REELS OFF 12 IN A ROW 

Things looked bleak for Konta as she lost the first four games against Zhang, but the Briton mounted a sparkling revival in dumping out the last Chinese player left in the draw.

Konta won 12 games in a row to seal victory and keep her hopes of a spot in Singapore very much intact.

"Even though it was 12 games in a row, the scoreline was a lot closer," Konta said. "Every single point was a really high level. I had to fight a lot at the end."