Tokyo - Italy's number one Fabio Fognini beat Japan's Yuichi Sugita in five hard-fought sets to give his country a 3-1 victory in their Davis Cup World tie at Morioka in Japan on Sunday.
Fognini, ranked 22nd in the world, edged past Sugita 3-6, 6-1, 3-6, 7-6, 7-5 in a marathon match lasting four hours and eight minutes to take Italy into the quarter-finals for the fifth time in six years.
The Italian had admitted feeling tired after Saturday's doubles success, having played nearly eight hours in total including Friday's defeat of Taro Daniel.
He even suggested he might not play on Sunday but managed to stay on court for another four hours with plenty of tiebreak tension.
Japan had hoped to reach the Davis Cup quarter-finals for only the second time after former world number four Kei Nishikori helped them reach the last eight in 2014.
But they will have to enter September's playoffs in a bid to remain among the Davis Cup elite.
Italy were champions back in 1976 and have finished runners-up on six occasions.
The tie was held in a 4,000-capacity indoor arena in snowy Morioka, some 450 kilometres (280 miles) north of Tokyo. The first-choice venue of Ariake in Tokyo is being renovated for the 2020 Olympic and Paralympic Games.