Sydney - Australian Open finalist Jo-Wilfried has hit an injury crisis with four days to go before the start of the tournament at Melbourne Park as a bad back forced him to withdraw ahead a match in Sydney on Thursday.

The pullout at the Medibank International sent Finn Jarkko Nieminen into the semi-finals, his first of the season and third in a year.

Tsonga had complained of back trouble during previous wins this week, but was unable to take to the court for his quarter-final against the 41st-ranked Finn.

Tsonga lost the Open final last January to Novak Djokovic, the Sydney top seed.

The run of four-time winner Lleyton Hewitt was ended by David Nalbandian in a re-match of the 2002 Wimbledon final, the Argentine winning 7-6 (7-3), 7-5.

Richard Gasquet won a French encounter over Jeremy Chardy 6-2, 7-6 (7-4).

Hewitt's match was interrupted by rain showers after just a few points with the pain later getting back on court.

Nalbandian managed to lift the first set in a tiebreaker and took a lead in the second on an early break. He was broken to love as he served for the match, but the South American pulled through three games later.

Hewitt is playing this month after undergoing August hip surgery and has all of his famed mobility back. (dpa)