After becoming the first player to win two singles titles this season in Stuttgart, Petra Kvitova has lengthened her lead atop the Porsche Race to Shenzhen. 

With no movement in terms of positioning in the Top 8, Kvitova's triumph extends her edge over No.2 Naomi Osaka, who was forced to give a walkover to Anett Kontaveit due to an abdominal injury in the semifinals, to nearly 650 points.

Kontaveit, the runner-up at the Premier-level event, does enjoy a move up to No.11 in the Race, a move up of five spots.

In addition, Stuttgart semifinalst Kiki Bertens, who took Kvitova to three sets, swaps spots with Simona Halep to round out this week's Top 10.

Elsewhere in the Race, Istanbul Cup champion Petra Martic soars 29 spots to No.24 after winning her first career title in the Turkish city.

Runner-up Marketa Vondrousova, who rises into the Top 40 in the WTA rankings this week, also makes gains in the Race.

The Czech teenager moves up four spots to No.16, having reached her fourth straight quarterfinal - and then some - in Istanbul.

Click here to see how the Porsche Race to Shenzhen in singles stands as of April 29: