Jannik Sinner isn't even allowed to play competitive tennis, yet he's still strengthened his grip as the world's leading men's player.

Sinner, of course, is almost halfway through a three-month ban for a doping offence, which ruled him out of the 'Sunshine Double' in Indian Wells and Miami.

But he watched on as nearest rivals - Alexander Zverev and Carlos Alcaraz - both fumbled the chance to significantly narrow the gap at the top of the ATP rankings.

It looks increasingly likely Sinner will lead the way when he returns in Rome at the start of May.

Sinner still holds a lead of 2,685 ranking points over Zverev, while Alcaraz is 3,610 adrift.

With 1,000 points available to the Monte Carlo and Madrid champions, plus 500 for winning Barcelona or Munich, a slim opportunity for Zverev remains.

Seizing the chance to overtake Sinner had been on Zverev's mind. Then he started, by his own admission, "playing terrible".