Kim Clijsters has announced her retirement from tennis for the third time.

Across a glittering career, the Belgian star won four Grand Slam singles titles and was formerly ranked as the number one player in the world. 

Having first retired in 2007, Clijsters made a remarkable return to the sport in 2009, before retiring again in 2012. 

Seven years later, she announced another comeback but persistent injuries coincided with the Covid-19 pandemic, rendering her unable to play consistently. As a result, the 38-year-old has called time on her career once more.

A fan favourite, who was renowned as one of the ‘nicest’ players on tour –– here are five of the Belgian’s most memorable moments: 

Becoming world number one

The 2003 season is often referred to as Clijsters’ ‘annus mirabilis’ [miraculous year]. She competed in 21 singles events; winning nine, advancing to the final in 15 and reaching at least the semi-finals in all but one. 

With 90 wins in total, Clijsters was the first player to accrue that many wins since Martina Navratilova in 1982. 

In August of that year, the Belgian became the world number one –– overtaking the great Serena Williams, who had struggled with injuries for most of the season. 

It meant that Clijsters became the first-ever number one ranked player to hold the position without winning a Grand Slam. 

Throughout her career, Clijsters held the number one ranking on four occasions and for a combined 20 weeks in total. 

First Grand Slam title

By 2005, Clijsters was undisputedly considered one of the best players on the tour but had still not captured a major title. 

This all changed at the US Open that year as she stormed to a historic victory in New York. 

Clijsters battled back from a set and a break down against Venus Williams in the quarter-finals, before defeating top seed Maria Sharapova in the semis. 

Facing Mary Pierce in the final, the Belgian conceded just four games and deservedly scooped the first of her three titles at Flushing Meadows. 

US Open 2009

Clijsters retired in 2007 to start a family but returned to the sport two years later. 

By the time the US Open came around, the former world number one was unranked and few expected her to challenge the dominant Williams sisters. 

Yet, Clijsters defeated both Venus and Serena to set up a final against Caroline Wozniacki. 

The Belgian then defeated the Danish star to win her second major title. 

Hall of Famer 

After her US Open success in 2009, Clijsters made her way back up the rankings and won two more Grand Slams –– first at the US Open again in 2010 and then the Australian Open in 2011. 

Along with Margaret Court, Clijsters holds the record for the most Grand Slam singles titles won as a mother with three. 

In 2017, she was inducted into the International Tennis Hall of Fame. 

Second comeback 

After retiring for the second time in 2012, Clijsters announced her shock return to tennis in February 2020. 

Unfortunately, however, the Covid-19 pandemic then disrupted the tour and halted Clijsters' comeback.

The Belgian was then forced to undergo knee surgery and did not play another match in 2020. 

Now, having managed to play just five matches in two years, the four-time major champion has retired from the game again –– citing a desire to focus more on her family.