The 1980 Suisse Open Gstaad was a men's tennis tournament played on outdoor clay courts in Gstaad, Switzerland.
 It was the 35th edition of the tournament and was held from 7 July through 13 July 1980.
 The tournament was part of the 1980 Volvo Grand Prix tennis circuit.
 Third-seeded Heinz Günthardt won the singles title.
Two time reigning champion Chris Evert did not defend her title.
 She would stay home and play WTT, and did not return to Paris until 1979.
 Sue Barker defeated Renáta Tomanová 6–2, 0–6, 6–2 in the final to win the Women's Singles tennis title at the 1976 French Open.
Renáta Tomanová (born 9 December 1954) is a former professional tennis player from Czechoslovakia.
Heinz Peter Günthardt (born 8 February 1959 in Zürich) is a former tennis player from Switzerland, who won five singles titles during his professional career, including the Rotterdam WCT in 1980.
Björn Borg was the defending champion of the singles event at the ABN World Tennis Tournament, but did not participate in this edition.
 Unseeded Heinz Günthardt won the title after a victory in the final against first-seeded Gene Mayer 6–2, 6–4.
Olga Zaitseva (born 12 March 1962) is a former competitor for the Soviet Union at the 1979, 1980, 1981 and 1983 editions of the Federation Cup.
 Despite posting doubles victories over top professionals such as Betty Stöve, Hana Mandlíková and Renáta Tomanová, Zaitseva did not compete at any point on the women's professional tennis circuit or at any of the Grand Slams and thus never attained a world ranking.
Heinz Günthardt was the defending champion of the singles event at the ABN World Tennis Tournament, but did not participate in this edition.
 First-seeded Jimmy Connors won the title after a victory in the final against second-seeded Gene Mayer 6–1, 2–6, 6–2.
The Men's Doubles tournament at the 1985 Wimbledon Championships was held from 24 June to 7 July 1985 on the outdoor grass courts at the All England Lawn Tennis in the district of Wimbledon in London, England.
 Peter Fleming and John McEnroe were the defending champions, but lost in the semifinals to Pat Cash and John Fitzgerald.
 Heinz Günthardt and Balázs Taróczy won the title, defeating Pat Cash and John Fitzgerald in the final.
The 1980 ABN World Tennis Tournament was a tennis tournament played on indoor carpet courts at Ahoy Rotterdam in the Netherlands.
 It was part of the 1980 Volvo Grand Prix circuit.
 It was the eight edition of the tournament and was held from 10 March through 16 March 1980.
 Unseeded Heinz Günthardt won the singles title.
Paul Vojtischek (born Pavel Vojtíšek, 13 June 1963) is a Czechoslovak-born West German retired professional tennis player.
 Vojtisek, who got West German citizenship in his early 20s, is married to two-time Grand Slam finalist Renáta Tomanová.

Question: Which tennis player is older, Heinz Günthardt or Renáta Tomanová?
Answer: Renáta Tomanová