(CNN)If you were a 37-year-old at the French Open Sunday, it was a day to remember. Roger Federer made a winning return to the clay-court grand slam after a three-year absence while Nicolas Mahut added to his noteworthy accomplishments after losing the longest tennis match in history, overcoming a two-set deficit to defeat last year’s surprise semifinalist Marco Cecchinato on the new Simonne Mathieu court. Defeat to John Isner at Wimbledon in 2010 wasn’t the end of Mahut, rather it served as the turning point in the Frenchman’s inspiring career. JUST WATCHED Tearful Roger Federer remembers late coach Replay More Videos … MUST WATCH Tearful Roger Federer remembers late coach 03:21 Federer’s own career, one in which he leads the men’s grand slam count on 20 and remains a viable threat at majors despite his advanced tennis years, has been inspiring too. That is, of course, a huge understatement. Read More Playing for three decades — he will probably reach a fourth — Federer first began as the young, temperamental upstart. Visit CNN Sport for more news and videos He soon became the most dominant player in tennis, later overtaken by Rafael Nadal and Novak Djokovic and subsequently overcame a…