Top seven youngest ATP Tour champions in Open Era

Lleyton Hewitt tops the list of youngest ATP Tour champions.

Tennis records keep breaking and this time it was the turn of young sensation Joao Fonseca. The Brazilian has at a young age captured the attention of a global audience and his recent heroics in Argentina have already placed him in the history books alongside legends of the game.

Fonesca had been building on to this moment for the past few months. At the recently concluded Australian Open, the Brazilian overcame a tricky qualifying round to advance to the main draw, without dropping a set. In his first-ever contest at Melbourne Park, Fonesca beat 10th seed Andrey Rublev to produce one of the greatest results in the sport’s history.

Also Read: Top six best individual seasons in tennis men’s singles

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.

On that note, let’s take a look at the seven youngest ATP tour champions in tennis history, following the launch of the ATP Tour in 1990.

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

Fonseca started the 2025 season ranked No. 145, a remarkable rise from No. 730 just 12 months earlier. He garnered global attention at the Australian Open 2025, where he overcame a tough qualifying group, without dropping a set. In his Grand Slam debut, Fonseca stunned 10th seed Andrey Rublev to stir a massive upset.

The Brazilian then scripted history at the Buenos Aires Open, winning his maiden ATP title and becoming the youngest ever to win an ATP singles title from South America. His heroics saw him achieve a career-high ranking of 68, along with prize money of $100,160.

Also Read: Top five youngest men’s singles players to achieve Career Grand Slam

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.

So the Canada Masters title is his first trophy in the ATP Tour era and he defeated top seed Andre Agassi 4-6, 7-5, 7-5 in the quarter-final and fifth seed Sampras 3-6, 7-6, 7-5 in the last four getting the better of fourth seed Jay Berger 4-6, 6-3, 7-6 loss in the final.

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. The Spaniard has already won 4 Grand Slams at the age of 21. In 2024, Alcaraz won Wimbledon and the French Open and claimed the silver medal in his debut Olympics in Paris.

As of February 2025, Carlos Alcaraz has won 17 ATP Tour singles titles, including four Grand Slam titles and five Masters 1000 titles. Currently ranked third in the world, the Spaniard is poised to become one of the finest ever to have played the sport.

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

Only two months after 18, Rafael Nadal entered a clay-court event called Sopat in Poland, as the sixth seed. The ‘King of Clay’ winner Nadal defeated Franco Squillari from Argentina and Spain’s Felix Mantilla en route to the final and then beat the unseeded Jose Acasuso 6-3, 6-4 to lift his maiden title.

The Spaniard finished 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.

Also Read: List of Grand Slams Rafael Nadal has missed due to injuries

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 announced himself to the world in style, downing fifth seed Florian Mayer in the first round, third seed Sam Querrey in the semi-final and finally beating top seed James Blake 3-6 6-1 6-4 in the final. Such was the extent of his heroics, that he climbed 122 spots on the ATP rankings to become the new 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 didn’t face any seeded players during his run to the final with Roldan also unseeded for the event.

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.

Also Read: Top six ATP players with highest winning percentage as World No. 1

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

Former World Number One is the youngest ATP winner in the game history, a feat he accomplished when he lifted the trophy in Adelaide at just 16 years old. The Australian competed in this tournament despite being at school then.

During his stunning campaign, Hewitt defeated the likes of Mark Woodforde, Vince Spadea and the great Andre Agassi during his incredible run to the final. He faced fellow Australian Jason Stoltenberg in the final and won 3-6, 6-3, 7-6 (7-4) to replace Medvedev as the youngest ATP Tour title winner, and continues to hold the record till today.

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