It was the opportunity Novak Djokovic had been waiting for. Jannik Sinner was on his way home before the third round. Carlos Alcaraz was absent, unable to defend his French Open title. At 39 and with his chances of winning a record 25th grand slam singles title running out, Djokovic’s two biggest rivals, who between them had won the last nine major titles and ended his quest at the last four attempts, had been cleared from his path. As the men’s draw in Paris was blown wide open, Djokovic was the only grand slam champion remaining in the tournament. But then Djokovic’s dream of grand slam history was ripped up by the arrival of a new star. At 19, Joao Fonseca claimed the biggest victory of his career in a stunning upset of historic proportions. Across four hours and 53 minutes, the Brazilian became the first teenager to beat Djokovic at a grand slam. He did it with power, poise, and from two sets down, winning 4-6, 4-6, 6-3, 7-5, 7-5.…