The Japanese top seed beat Gil, who had reached the second round of a wheelchair tennis Super Series tournament for the first time, 6-0, 6-0 to book his place in the last eight at the Lamar Tennis Center.

Kunieda, a double Paralympic Games singles gold medallist, will take on Stefan Olsson of Sweden in the quarter-finals.

Olsson needed three sets to overcame Dutch player Tom Egerbrink as he recovered from dropping the opener to claim a 5-7, 6-3, 6-3 win.

Elsewhere in the men's singles draw, Gustavo Fernandez of Argentina, seeded second, was also made to work hard for his spot in the last eight.

Fernandez lost the first set but rallied to beat Japan's Takashi Sanada 4-6, 7-6, 6-4.

Britain's Alfie Hewett is also through as the fourth seed dispatched Frederic Cattaneo of France 6-4, 6-4.

In the women's draw, top seed Diede de Groot of The Netherlands comfortably progressed with a dominant 6-0, 6-1 victory over Maria Florencia Moreno of Argentina.

De Groot will next face Macarena Cabrillana after the Chilean caused an upset by defeating eighth seed Manami Tanaka of Japan 7-6, 2-6, 7-6.

Sixth seed Katharina Kruger of Germany is also out as she lost 6-1, 6-1 to American Dana Mathewson.

Second seed Aniek van Koot joined compatriot De Groot in the last eight as she earned a 6-4, 6-1 win against Colombia's Angelica Bernal.

Both of the top seeds in the quads tournament progressed comfortably.

American top seed David Wagner beat Britain's James Shaw 6-0, 6-0 and Koji Sugeno of Japan, the second seed, saw off compatriot Shota Kawano 6-4, 6-0.

The tournament in Louisiana continues tomorrow.