STUTTGART, Germany (REUTERS) - American CoCo Vandeweghe produced a merciless display on her least favourite surface to beat compatriot Sloane Stephens 6-1 6-0 in the opening round of the Porsche Tennis Grand Prix in Stuttgart on Wednesday (April 25).

Vandeweghe, who had teamed up with Stephens last weekend to help the US defeat France and reach the Fed Cup final, was broken to love in the first game.

Yet the US Open champion Stephens dropped her own serve in the next game as Vandeweghe reeled off 12 consecutive games to wrap up victory in 56 minutes.

Vandeweghe, ranked 16 in the world, recorded her first victory over Stephens on clay, having lost their only previous encounter on the surface in Strasbourg in 2015.

"I really don't like clay, it's my least favourite surface," Vandeweghe, who will meet Laura Siegemund in the next round, said after the match.

"I'll never like it. This is my second time in Germany - I'm not here for the clay, it's more the shopping. I didn't come out here to play and lose."

Russian Anastasia Pavlyuchenkova battled past US Open runner-up Madison Keys 7-6(7) 5-7 6-4.

The 26-year-old will take on second-seed Garbine Muguruza in the second round.