 Complete the following phrase:  Tikhomirova had four straight pentathlon wins at national level from 1969 to 1972, including a championship best of 5120 at the 1971 Spartakiade, which was never bettered the heptathlon replaced the pentathlon the programme in 1981. She remained among the worlds best in her event, but narrowly missed out on further medals in the rest of her career, placing fourth at the 