Nicolas Peifer upset the top seed today ©Getty Images

Nicolas Peifer stunned top-seed Gustavo Fernandez in a repeat of last year's final at the Australian Open wheelchair tennis tournament in Melbourne Park.

France's Peifer avenged his loss last year by triumphing 4-6, 6-3, 6-2 against the Argentine in the quarter-finals.

It means that Fernandez will also lose his position at the top of the world rankings.

He had needed to win the tournament to maintain his position.

French Open champion Alfie Hewett will replace him despite himself suffering a disappointing loss today elsewhere in the quarter-finals.

The Briton was beaten 1-6, 6-3, 6-4 by Swede Stefan Olsson.

Alfie Hewett will become the world number one despite his loss today ©Getty Images
Alfie Hewett will become the world number one despite his loss today ©Getty Images

In a disappointing day for the British, world number four Gordon Reid was also thrashed 6-1, 6-3 by Shingo Kuneida of Japan.

France's Stephane Houdet completed the semi-final line-up by beating home hope Adam Kellerman, 6-2, 6-0.

There were no such problems for the top seeds in the corresponding women's draw.

Top-ranked Japanese star Yui Kamiji won 6-3, 7-5 against Marjolein Buis while The Netherlands' Diede de Groot beat Germany's Katharina Kruger 6-1, 6-1.