Karppinen defended his Olympic title at the 1980 Olympic Games in Moscow, this time besting Vassily Yakusha by more than two seconds. Kolbe had missed the 1980 Games in Moscow because of the anti-Soviet boycott, but he was back to challenge Karppinen on Lake Casitas during the Olympic Games in Los Angeles in 1984. Kolbe took the early lead, but again Karppinen came from behind, catching Kolbe 250m from the finish and then powering ahead in the last 25m to earn his third gold medal.
Karppinen also competed in the 1988 and 1992 editions of the Games, placing seventh and tenth respectively. He is one of only two rowers (Vyacheslav Ivanov being the other) to win the Olympic single sculls three times.