The coach of Arthur Rinderknech, a player who shocked the tennis world, stunned Rafael Nadal at the US Open in 2016. This year, Rinderknech has been making waves at the Shanghai Masters, reaching his first career Masters 1000 final after beating top players like Daniil Medvedev, Alexander Zverev, and Felix Auger-Aliassime. However, his journey to the final was bittersweet, as he faced and lost to his cousin, Valentin Vacherot, in the Shanghai Masters final. But the real story lies in the coach's past. In 2016, Nadal faced a challenging year due to a wrist injury, which forced him to withdraw from the Roland Garros and Wimbledon. At the US Open, he made a strong comeback, reaching the fourth round without losing a set. That's when he encountered Lucas Pouille, a 24th-seeded Frenchman, in a match that would become a turning point in Pouille's career. Pouille, who had already reached the Wimbledon quarterfinals that year, led Nadal by two sets to one but ultimately lost in a five-set thriller on Arthur Ashe Stadium. This loss marked the end of a difficult Grand Slam season for Nadal, while Pouille's performance propelled him to new heights. Pouille's success continued, as he won his first ATP title shortly after the US Open and finished the year ranked world number 15. He went on to win three more titles in 2017 and made his top 10 debut in March 2018, reaching a career-high ranking of world number 10. However, Pouille's journey took a turn in 2025 when he ruptured his Achilles tendon during a Challenger tournament final, which he admitted could be a career-ending injury. Despite this setback, Pouille has recently returned to coaching Rinderknech, and his guidance seems to be paying off, as Rinderknech has reached a career-high ranking after his Shanghai Masters final appearance. The story of Arthur Rinderknech and his coach is a testament to the power of perseverance and the potential for growth in the world of tennis.