After Bartkowicz found a tennis racket in a bush at the age of seven, she started playing tennis. She was nicknamed "Peaches" by one of her tennis coaches, Richard Sunday, who said she had a peach of a shot . She won her first singles and doubles titles in 1960 with the US Lawn Tennis Association. Between the ages of eleven and seventeen she won 17 national junior tournaments; In 1964 she won the girls’s Wimbledon Championships. In 1969 she won the Federation Cup with the US team and in 1970 the Wightman Cup . She won a total of 14 tournaments and reached 8th place in the world rankings in 1969.
At the demonstration competition of the 1968 Olympic Games in Mexico , Bartkowicz won the gold medal in singles.