PORTO: Portugal's victory in the inaugural Nations League sparked celebrations long into the night in Porto on Sunday, but the hosts were far from the only ones happy at the end of UEFA's attempt to add more competition to the international calendar.

A complex format that saw UEFA's 55 nations split into four tiers with promotion and relegation on offer, as well as the chance of a playoff to qualify for next year's European Championships, took some time to get used to.

England's Harry Maguire even admitted before the Three Lions opening game of the competition against Spain that he did not fully understand the format.

Yet, that skepticism was washed away once the games got under way with competitive football between nations of a similar level replacing meaningless friendlies and often one-sided qualifiers.

"I think it is a great tournament," said Ronald Koeman, whose Netherlands side was beaten 1-0 by Portugal in Sunday's final.

"The intensity in the groups was really high and the idea to organize the Nations League was a perfect one. We are looking forward to the next one."

For all four sides who made the semi-finals in Portugal, the past week may well also prove to be the perfect launching pad to next summer's European Championships.

Portugal look a better side than when they won Euro 2016 with a host of young talent led by Bernardo Silva, Bruno Fernandes and Ruben Dias to ease the burden on a 34-year-old Cristiano Ronaldo.

After missing out on the last two major tournaments, the Netherlands gained some vital experience, even if they did fall at the final hurdle after beating world champions France, Germany and England to make the final.

England built on the success of reaching the semifinals at last year's World Cup by beating Spain and Croatia in the group stages, while Switzerland could easily have upset Portugal in the semifinals with better finishing.

"I am sure this tournament will become a classic because it is a tournament for the entire European family," said Portugal coach Fernando Santos. "To be the first winner will go down in history."

More than 20,000 travelling fans came to northern Portugal from England, The Netherlands and Switzerland in the past week to show that supporters had also been won over.

Yet, the success of the Nations League is likely to stir up more conflict in the continuous battle between club and country.

Liverpool manager Jurgen Klopp has been the most outspoken critic of adding a new competition at a time when top players are already being burned out by the demands of long, intense seasons at club level.

"If we don't learn to deal with our players in a better way, competition-wise, then it's the only chance to kill this wonderful game," said Klopp last month. "Because without the players, it's not a good one."

England's preparation for the past week was seriously affected with seven players in Gareth Southgate's 23-man squad involved in the Champions League final and all were left out from the start in defeat against the Dutch.

Yet, had England not reached the Nations League finals, they would have had two more qualifiers for the European Championships this week in a six-team group rather than five.

And having scored 10 goals in winning their opening two qualifiers, Southgate believes the Nations League is far more appealing to players, coaches and fans alike.

"We could be playing qualifying matches somewhere else tonight," he said after a second semi-final defeat in 12 months. "We weren't, we were playing another semifinal."