Teenager Gauff will face the unseeded Martina Trevisan for a place in the final after beating her compatriot 7-5 6-2 at Roland Garros on Wednesday (AEST).

The composed 18-year-old has not dropped a set in Paris and produced another assured display on Court Phillipe-Chatrier to break new ground.

Eighth seed Gauff was rewarded for an aggressive display, breaking six times as Stephens paid the price for being too passive in a contest that was over in 90 minutes.

Gauff started with huge confidence, racing into a 3-0 lead courtesy of some heavy hitting while creating great angles.

Stephens clicked into gear with a more aggressive approach, winning three games in a row from 5-2 down as Gauff was unable to serve out the set.

The teenager halted with momentum with a hold and wrapped up the set with a backhand winner after the 2017 US Open champion made a mess of a volley at the net.

Stephens came out firing to break in the first game of the second set, but Gauff hit straight back to get back on serve and led 3-1 after ending another point she dictated with a cross-court backhand winner.

The 64th-ranked Stephens was gifted a chance to get back on serve when Gauff presented her with a simple volley at the net, but she inexplicably drilled it long and the youngster held for a 4-1 lead after saving three break points.

Gauff had won five games in a row and was on the brink of victory when her opponent crashed a forehand into the net, and although she failed to serve out the match in a nervy game, she broke for a fourth time in the second set to seal it.