Arsene Wenger believes Leicester City's Premier League title win is the most remarkable event during his time in English football.
Wenger led Arsenal to title glory in 2003-04, when his "Invincibles" went through the entire league season without suffering a defeat.
That was the last time Arsenal lifted the top prize and, speaking ahead of Sunday's match against Manchester City where the Gunners will aim to secure Champions League qualification for next season, Wenger reflected on a stunning season that has challenged many accepted norms.
"Yes, it's the most unexpected event since I've been in England and the biggest achievement I've seen here," he said.
"It's a remarkable achievement and the fact that their success is based on team spirit, on the real deep qualities of our game, makes it even more fantastic.
"They lost only three games and that's remarkable, looking at the quality of the competitors you have.
"It's done in an unusual way and it must give us some food for thought because they had low possession. That's very unusual.
"Possession in time was not so high, the [passing] accuracy was not the best. But they were very good at what they did - strong in defence, excellent on the counter-attack.
"It's unexpected. Will it last and set a trend for the coming seasons? I don't know."
Two of Leicester's three losses came at the hands of Arsenal, but Wenger's men were unable to sustain a title challenge after putting themselves in prime position with a February win over Claudio Ranieri's side at Emirates Stadium in February.
"Yes [we beat Leicester twice] but that means the other clubs didn't do their job as well as we did against them. When you don't finish first you have regrets
"Against the top four I think we are in a very strong position. We dropped points against other teams not in the top four or top five."
Victory on Sunday would keep Arsenal's hopes of finishing above second-place Tottenham alive, having not ended a season below their north London rivals during Wenger's 20-year tenure.
"It's not over, let's see what happens until the end of the season," he added. "Tottenham have had a good season - they didn't manage to finish very strongly recently but they have a good team
"Our target is still to finish in front of them.
"If [Tottenham finish above Arsenal] you can at least say it's a one off because it has not happened in 20 years. We will fight until the end to make sure we have a chance of coming second."