Saensak started fighting in Muay Thai and fought in several Muay Thai matches held in Japan prior to winning the world title. In the beginning, he used the name "Saensaep Petchcharoen" and "Saepsuang Petchcharoen" in his neighborhood. Later, he became a famous Muay Thai fighter. He has faced many top Muay Thai fighters such as Pud Lorleg, Vicharnnoi Porntawee, Putpadnoi Warrawut, Kunpol Sakornpitak, Wisan Graigreangyuk, Kongdej Lookbangplasroy, Sirimongkol Looksiripat, and he won the junior welterweight title by knockout from Sorrasak Sor Lukbookalo in just the first round in 1971. In addition, he was also an amateur boxer at the 7th Southeast Asian Peninsular Games in Singapore in 1973. He made news every time he won by RSC until he won the gold medal. Saensak made his formal professional boxing debut on November 16, 1974, with a first-round knockout win. He won his second fight in February 1975 by technical knockout in round 7, and challenged Perico Fernandez for the WBC light welterweight title in his third professional fight. He defeated Fernandez by technical knockout in the 8th round on July 15, 1975, to set a world record for taking the shortest time to win the world title; it had been less than a year since he made his debut in 1974. Saensak lost his world title in his second defense against Miguel Velasquez after being disqualified in the 5th round, but quickly regained it four months later on October 29, 1976, by knocking out Velázquez in two rounds. He successfully defended the WBC belt 7 times, most notably against former WBC lightweight championGuts Ishimatsu, whom he knocked out in six rounds. He was knocked out by Sang Hyun Kim in the 13th round to lose his world title on December 30, 1978. He fell into relative obscurity from then on, losing both of his fights in 1979, one of which was a third-round knockout loss to Thomas Hearns. His last professional fight was for the OPBFwelterweight title, which he lost by decision over 12 rounds. His record was 14–6–0. In 2014 Vasyl Lomachenko equaled the record of winning a world title in his third bout. Saensak still has the record for the fastest time though, having taken 11 days less than the Ukrainian.
Professional record
Personal life & Death
During the glory period he was a celebrity or even a superstar. He married a popular actress in that era, Prim Prapaporn. The couple have one son, he named his son Kriangsak "King" Mansri, just like the name of the prime minister at the time Gen. Kriangsak Chamanan. He ended his boxing career with injuries, especially the right eye. When he retired, he was blind in his right eye. His wife divorced him, and his savings of up to 10 million baht were exhausted. Ever since, his life has been hard. He had a monthly courtesy from the WBC and other authorities in Thailand, but it was not enough to cover costs. Saensak was admitted to Rajvithi Hospital on April 12, 2009 for liver failure and intestinal blockage. Surgery failed to improve his condition, which was complicated by Saensak being afflicted by various ailments. On April 16, Saensak died while under observation in an intensive care unit.
