Top seven youngest ATP Tour champions in Open Era

Tennis records keep breaking and this time, the spotlight is on the young prodigy Joao Fonseca. The Brazilian has captured global attention at a remarkably young age, and his recent achievements in Argentina have secured his place in the annals of tennis history alongside legends of the game.

Fonseca had been building on to this moment for the past few months. During the recently held Australian Open, the Brazilian successfully navigated a challenging qualifying round to reach the main draw, achieving this feat without losing a single set. In his first match at Melbourne Park, Fonseca triumphed over the 10th seed, Andrey Rublev, delivering one of the most remarkable outcomes in the history of the sport.

On February 16, Joao Fonseca became the youngest South American to win an ATP event since 1990, defeating local favorite and 26th-ranked Francisco Cerundolo, to lift his maiden ATP title, in Argentina.

In this article, let’s take a look at the seven youngest ATP tour champions in tennis history, since the inception of the ATP Tour in 1990.

7. Joao Fonseca – 18 years, 5 months, 26 days

Fonseca started the 2025 season with a ranking of No. 145, a remarkable rise from his position of No. 730 just a year prior. He attracted international attention during the Australian Open 2025, successfully navigating a challenging qualifying round without losing a single set. In his Grand Slam debut, Fonseca stunned 10th seed Andrey Rublev to stir a massive upset.

The Brazilian then made history at the Buenos Aires Open by securing his first ATP title, thereby becoming the youngest player from South America to win an ATP singles title. His heroics saw him achieve a career-high ranking of 68, along with prize money of $100,160.

6. Michael Chang – 18 years, 5 months, 1 day

Michael Chang remains the youngest man to win a Grand Slam as he was 17 years, 3 months, and 7 days old when he won the French Open in 1989. However, that happened before the launch of the ATP Tour in 1990 and Chang won four titles before 1990.

The Canada Masters title marks his first trophy in the ATP Tour era. He triumphed over top seed Andre Agassi with scores of 4-6, 7-5, 7-5 in the quarter-finals, and overcame fifth seed Pete Sampras 3-6, 7-6, 7-5 in the semi-finals. However, he faced a defeat against fourth seed Jay Berger in the final, with a scoreline of 4-6, 6-3, 7-6.

5. Carlos Alcaraz – 18 years, 2 months, 20 days

Carlos Alcaraz won his maiden ATP title against 35-year-old Richard Gasquet in the final of the Croatia Open. At just 21 years of age, the Spaniard has already won four Grand Slams. In 2024, Alcaraz triumphed at both Wimbledon and the French Open, and he also earned a silver medal during his first Olympic appearance in Paris.

As of February 2025, Carlos Alcaraz has won 17 ATP Tour singles titles, which encompass four Grand Slam victories and five Masters 1000 titles. Presently holding the third position in the global rankings, the Spanish player is on track to be regarded as one of the greatest ever to have played the sport.

4. Rafael Nadal – 18 years, 2 months, 6 days

Just two months after turning 18, Rafael Nadal entered in a clay-court event known as Sopat in Poland, where he was seeded sixth. The 'King of Clay' triumphed over Franco Squillari from Argentina and Spain's Felix Mantilla on his way to the final. He then defeated the unseeded Jose Acasuso 6-3, 6-4 to lift his maiden title.

The Spaniard concluded his illustrious career with 92 ATP singles titles, including 22 Grand Slam titles, 36 ATP Masters 1000 titles and two Olympic Gold medals, one each in singles and doubles.

3. Kei Nishikori – 18 years, 1 month, 13 days

Japan’s all-time great, Kei Nishikori entered the 2008 Delray Beach event ranked 244. He made a remarkable impression by defeating fifth seed Florian Mayer in the opening round, overcoming third seed Sam Querrey in the semi-finals, and ultimately triumphing over top seed James Blake with a score of 3-6, 6-1, 6-4 in the final match. His outstanding performance propelled him up the ATP rankings by 122 positions, earning him the title of World Number 122.

2. Andrei Medvedev – 17 years, 9 months, 15 days

Andrei Medvedev crushed Argentinian Guillermo Perez Roldan 6-3, 6-4 in the final of the Genoa 1992 event to become the youngest-ever player to win an ATP World Tour title. The young Ukrainian did not encounter any seeded players on his path to the final, while Roldan was also unseeded in the tournament.

Medvedev went on to win 11 ATP singles titles and lifted eight of those trophies before he turned 20. He also finished runner-up at the 1999 French Open.

1. Lleyton Hewitt – 16 years, 10 months, 9 days

The former World Number One holds the record as the youngest ATP champion in the history of the sport, achieving this remarkable milestone by winning the trophy in Adelaide at the age of 16. The Australian competed in this tournament despite being at school then.

Throughout his remarkable campaign, Hewitt defeated notable players like Mark Woodforde, Vince Spadea, and the legendary Andre Agassi on his extraordinary journey to the final. In the final, he confronted fellow Australian Jason Stoltenberg, securing victory with a score of 3-6, 6-3, 7-6 (7-4). This achievement allowed him to surpass Medvedev as the youngest ATP Tour title holder, a record he still maintains to this day.

Cover Credits - ATP Tour