Aleix: ‘My best performance in the wet’, Vinales down at Turn 1

The factory Aprilia rider took the lead after his bike swap, before being shuffled back to sixth place as the rain eased.

But as conditions worsened, Espargaro’s soft rear - most other frontrunners were on the medium - began to pay off once again.

However, the rain became too extreme, and the race was halted at half distance, with Espargaro in fifth.

But with Johann Zarco not classified after his late fall, Espargaro’s 11 points also handed him fifth place in the world championship.

"All told, a positive day with perhaps my best performance in the wet,” Espargaro said. “After the bike change, we had chosen the soft rear tyre, counting on the fact that when it rains it pours here in Motegi.

“Instead, on the first laps it was difficult. With not much water on the track, the soft tyre overheated and I was afraid I wouldn’t be able to finish the race. However, when the rain increased, I began to feel increasingly better.

“I was making up ground on the riders ahead of me and could have aimed for something higher than fifth place. Unfortunately, visibility was really low and it got even worse after the red flag and the restart.

“The decisions taken by Race Direction today were impeccable."

Vinales: ‘My race was over on the first corner’

Team-mate Maverick Vinales saw his Motegi chances end after contact at a perilous first corner, which riders approached using slick tyres in the increasing rain.

Marco Bezzecchi had to sit up his VR46 machine to avoid the back wheel of Francesco Bagnaia, causing contact with Vinales, who became sandwiched between Bezzecchi and Johann Zarco.

While the others remained on two wheels, Vinales then fell in the gravel, rejoining in last, where he remained.

The cancellation of a restart then ended any hope of points.

"My race was over on the first corner when I was forced wide into the gravel, crashing and restarting last with a huge gap,” Vinales said.

“After the bike change, to be honest, my pace in the wet was extremely good, but with so much distance to make up, it would not have been an easy race.

“I was hopeful for the restart after the red flag. Even though I would have started from pit lane, at least I would have had another chance."

Vinales is seventh in the world championship, 23 points behind Zarco.