In the 1988–89 season Furuseth performed consistently well. He opened with a ninth place in Sestriere in December, then improved gradually until reaching the podium for the first time, with a second place from Adelboden in January. He also won the slalom run in the Alpine Combined Event at the FIS Alpine Skiing World Championships. On 3 March in Furano, he finished second in the giant slalom, winning the slalom race two days later. One week later in Shigakogen, he won the giant slalom race and finished second in the slalom. As a result, he won the Giant Slalom Cup that year, though jointly with Pirmin Zurbriggen. In the Slalom Cup he finished third, and in the overall standings he finished fourth. He also competed at the 1989 World Championships, placing eighth in the giant slalom and sixth in the slalom. He was given the Norwegian Sportsperson of the Year award of 1989.