PARIS — The tennis world watched in stunned silence as Jannik Sinner, the 2023 US Open champion and world No. 2, collapsed in a five-set marathon against Alex Molcanov at Roland Garros. What unfolded on Court Suzanne Lenglen wasn’t just another grueling clay-court battle—it was a rare public display of the mental fragility that has long haunted the Belgian’s performance in high-pressure, five-set matches.

Now, former world No. 1 Boris Becker has offered a blunt explanation: “It all came from his head.” In an interview with Sport1, Becker—who knows firsthand the psychological toll of five-set battles—suggested Sinner’s struggles stem from an inability to sustain focus over marathon sessions, a weakness that aligns with his 0-4 record in five-set matches at Grand Slams.

Why this matters: Sinner’s exit marks the first time since 2021 that a top-five player has fallen in the second round of the French Open. His collapse raises critical questions about the modern game’s physical and mental demands, particularly on clay, where matches can stretch beyond four hours. For Sinner, who has spent years refining his aggressive baseline game, the psychological battle may now be as important as the tactical one.

Boris Becker’s Psychological Diagnosis: “It All Came from His Head”

Becker’s assessment—delivered with the bluntness of a man who won six Grand Slam titles—carries weight. The seven-time major champion has long emphasized the mental game in tennis, famously crediting his 1985 Wimbledon triumph to his ability to “switch off” opponents. For Sinner, however, the opposite may be true.

“When you play five sets, it’s not just about your body. It’s about your mind staying sharp for 4, 5, 6 hours. Jannik has shown he can do it in some matches, but in others… It’s like he just gives up.”

Sinner’s performance against Molcanov—where he led 6-4, 4-0 before losing 19 of the next 21 games—mirrors his pattern in five-set matches. Records show he has