Club Born in
Gerlafingen, Kunz started his football with the youth teams of the local football club
FC Gerlafingen, advancing to their first team in summer 1962. One year later he was signed by
Basel for their
1963–64 season under head coach
Jiří Sobotka. Kunz came as reserve goalkeeper behind
Kurt Stettler, who had been the team's goalkeeper since 1957 and who stayed as first choice goalkeeper until 1965. Kunz made his very first appearance for the team on 10 August 1963 in a friendly game against FC Gerlafingen to say thank you for the transfer, which FCB won 4–1. Kunz played his
domestic league debut for Basel on 8 September 1963 in the 1–0 away win against
Grenchen. In his fourth league match, in April 1964, he broke his arm during the game against
Schaffhausen, which forced him out of the game for some time. To the beginning of the
1965–66 season Helmut Benthaus transferred in from
1. FC Köln and became FCB's
player-coach. He replaced
Jiří Sobotka as team manager. Benthaus consolidated the internal goalkeeping hierarchy, after Sobotka had never been able to make a clear decision between
Jean-Paul Laufenburger,
Hans-Ruedi Günthardt and Kunz in the previous season. From here on, Kunz was number 1 between the posts and it remained that way for the following ten seasons, even if Laufenburger and later the young up-and-coming
Hans Müller were also very reliable when there was a change due to injury or for reasons of form. Kunz won the Swiss championship title for the first time in
Basel's 1966–67 season. Basel finished the championship one point clear of
FC Zürich who finished in second position. Basel won 16 of the 26 games, drawing eight, losing twice, and they scored 60 goals conceding just 20 and Kunz held a
clean sheet on 12 occasions. In that season Kunz won the
double with Basel. In the Cup final on 15 May 1967 Basel's opponents were
Lausanne-Sports. In the former
Wankdorf Stadium,
Helmut Hauser scored the decisive goal via penalty. The game went down in football history due to the sit-down strike that followed this goal. After 88 minutes of play, with the score at 1–1, referee
Karl Göppel awarded Basel a controversial penalty.
André Grobéty had pushed Hauser gently in the back and Hauser let himself drop theatrically. Subsequently, after the 2–1 lead for Basel the Lausanne players refused to resume the game and they sat down demonstratively on the pitch. The referee had to abandon the match. Basel were awarded the cup with a 3–0 forfait. Kunz won his second title in
Basel's 1968–69 season. Basel finished the championship just one point clear of second placed
Lausanne-Sports. Basel won 13 of the 26 games, drawing ten, losing three times, they scored 48 goals conceding 28 and Kunz held a clean sheet on seven times in 18 outings. Kunz won the championship with Basel for the third time
season 1969–70. The team again finished one point clear of Lausanne-Sports who ended in second position. Basel won 15 of the 26 games, drawing seven, losing four times, they scored 59 goals conceding 23 and Kunz held a clean sheet 10 times in his 26 appearances. In
1971–72 Kunz won the championship for the fourth time. Basel ended the season four points ahead of
Zürich. Of the 26 league games Basel won 18, drawing seven, losing just once, scoring 66 goals conceding 28 and Kunz held a clean sheet on eight occasions. Kunz won the Swiss championship title for the fifth time in the
1972–73 Nationalliga A season. Basel won the championship four points ahead of
Grasshopper Club. Basel won 17 of their 26 league games, drew five and lost four. They scored a total of 57 goals conceding 30. Kunz held a clean sheet six times in his 18 outings. The
1972 Swiss League Cup was the inaugural
Swiss League Cup competition. It was played in the summer of 1972 as a pre-season tournament to the
1972–73 Swiss football season. Basel beat
Servette 8–0,
Lausanne Sports 2–1
aet and
Sion 6–1 to reach the final. This was won by Basel who defeated
FC Winterthur 4–1 in the final which took place on 11 November 1972 at the
Letzigrund in
Zürich.
Ottmar Hitzfeld scored a hattrick in the final. A further curious fact to this final is that Kunz stood between the posts for the first half and
Jean-Paul Laufenburger was goalie for the second half. In addition to the five championship titles that he won, there were five cup finals in which Kunz was number 1 goalie in the FCB team. In his first cup final participation, mentioned above, against Lausanne-Sports and in his last in 1975, as Basel beat
Winterthur 2–1 after extra time, he was part of the winning team. However, in between there were the three cup final defeats against
FCZ, in all of which, Kunz suffered. Between the years 1963 and 1975 Kunz played a total of 373 games for Basel. 200 of these games were in the
Swiss Super League, 47 in the knock-out competitions (
Swiss Cup and
Swiss League Cup) 36 in the UEFA competitions (
European Cup,
UEFA Cup,
Inter-Cities Fairs Cup and
Cup of the Alps) and 90 were friendly games. After his career with FC Basel, Kunz played another season with
Nordstern Basel in the
Nationalliga B and then retired from active football completely. The following seasons he worked as coach for the amateur clubs FC Langenthal, FC Oberwil, FC Riehen, FC Nordstern und SC Kleinhüningen. ==Personal life==