In 1952 he entered only one race, the 50km, but he won that one by 4 minutes 38 seconds. At the 1956 Winter Games, a new event was added: the 30km race. Hakulinen won by 24 seconds. He also finished fourth in the 15km event and earned silver medals in both the 50km and the 4x10km relay.
By the time of the 1960 Olympic Winter Games in Squaw Valley, Hakulinen was 35 years old. He began quietly, placing sixth in the 30km and taking the bronze medal in the 15km. Two days later he staged his most memorable Olympic exploit. As the anchor of the Finnish relay team, Hakulinen took off 20 seconds after Norway's Hakon Brusveen, who had won the 15km race. With two kilometres to go in the relay, Hakulinen overhauled Brusveen, but the Norwegian pulled back into the lead. One hundred metres from the finish line, Hakulinen made his final move. Edging ahead in the last strides, he won by one metre. In his final Olympic appearance, two days after the relay, Hakulinen earned a silver medal in the 50km race.