month and 18 days old. Holger also competed in the 2019 Amersfoort Challenger in July where he captured his second ATP Challenger match win. On 28 October 2019 he achieved a ITF juniors ranking of World No. 1 after he defeated Harold Mayot to win the ITF Junior Finals. Rune served as a practice partner at the 2019 ATP Finals. Professional career 2020: First ITF title, Top 500 debut Rune officially turned pro in 2020 at the age of 16. At the 2020 Auckland Open, Rune received a wildcard into the qualifying draw but lost to Vasek Pospisil in straight sets. In July 2020, Holger became the youngest player to compete at the Ultimate Tennis Showdown (UTS), where he was defeated by French player Corentin Moutet. In September 2020, Rune won his first ITF title at an M25 event in Switzerland. He would make three more ITF finals by the end of 2020, winning two of the three. In October 2020, Rune received a wildcard to the ATP Challenger 80 in Puente Romano in Marbella, AnyTech365 Marbella Tennis Open. He lost 1-2 (6-1,4-6,4-6) in the first round to Elliot Benchetrit. 2021: ATP debut & first win, Four Challenger titles, top 110 Rune made three more ITF finals at the start of 2021, winning one. In March 2021, Rune made his ATP debut as a wildcard in the Argentina Open. He lost in the first round to fifth seeded Albert Ramos Viñolas in three sets. At the Chile Open the next week, Rune was accepted into the qualifying draw as a wildcard. He went on to win the qualifying round and record his first ATP match win against Sebastián Báez in straight sets. He followed this up with his first top-30 victory over Benoît Paire in straight sets to reach his first ATP quarterfinal, where he lost to Federico Delbonis in straight sets. At the age of 17, he became the youngest ATP Tour quarterfinalist since 2014. In June 2021, Rune won his first ATP Challenger title in Biella. His victory was overshadowed by homophobic slurs he made during his semi-final match. His actions were investigated by the ATP, and he was fined for his homophobic outburst. In July 2021, Rune received another wave of wildcards into several clay-court events during the summer clay-court swing: the Swedish Open, Croatia Open, and Austrian Open Kitzbühel. He posted a few more match wins