India, May 28 -- There were many moments when Jannik Sinner looked like he was about to throw his racquet in frustration on court. And many more when his racquet did not make a sweet connection with the ball.

In the first point of the fifth set, Sinner - a player who clings to the baseline - floated up to the net to try and serve-and-volley. He has done that a few times in his career, but on Thursday, under a blazing Parisian sun, the tactic came out of desperation. His legs had given up, and he was trying everything he could to keep the points short.

At the other end of the court, Juan Manuel Cerundolo spotted Sinner's charge up the court. The return was an attempted lob that was a touch deeper than the Italian would have liked. Sinner...