Gunnestad first came to prominence in 1988 when he won his first Norwegian title at the age of 17. His first British club was Sheffield in 1991, who competed in the British League Division Two. Gunnestad missed the British speedway season in 1992, but returned in 1993 when he was signed by British League team the Poole Pirates with whom he would spend this rest of his British career. Gunnestad became a popular rider at Poole and eventually received a testimonial meeting there in 2001. He appeared in five Speedway Grand Prix meetings as a wild card.