The 29-year-old Sousa, ranked 68th in the world, needed to call upon his reserves to claim the opening set by saving three break points in the final game.

Serving for victory at 5-2 in the second, the Portuguese was broken as Tiafoe briefly delayed the festivities.

But the local hero came good two games later as he clinched a third career title, a feat which quickly got the mainly Portuguese crowd into the mood for a mass sing-along chorus of celebration.

“This is fantastic, it’s such a special win, especially coming at home,” Sousa said. “I’m so proud to win here.”

“There are no words to describe this emotion, the fans were fantastic all week. It was incredible, it was a dream come true.”

“I always wanted to win here in Portugal.”

The previous Portuguese high point at the event came in 2010 when Fred Gil played the final, losing to Albert Montañés of Spain.

Tiafoe, realising how much the victory meant to his opponent, crossed the net to speak with Sousa and congratulate him.

“I knew how big this is for him, it would be big for me if I won. The whole country was behind him, I’m sure he felt that all week,” Tiafoe said.

“He’s massive here, it’s huge that he won. He played too good, too tough for me.”

“I’m happy for him, he’s one of the nicest guys on the tour.”

The world number 64 fell short in the end as he failed to generate the momentum which had kept him in clay contention all week.

Sousa improved to 18-10 this season after a poor start which he turned around with consistent results starting in March.

Sousa made a fast start as he produced a break of Tiafoe in the third game of the opener to take a 2-1 lead which he held throughout as the set progressed on level-pegging.

But Tiafoe suddenly struck, putting the Portuguese into a hole and facing three break points in the 10th game of the set.

Sousa calmly saved all three, then earned a set point before closing it out by winning his fifth straight point to take the lead 6-4 after 40 minutes.

Sousa, sensing his chances, broke to start the second set, putting his less experienced opponent on the back foot.

It quickly went to 2-0 as Tiafoe’s mistakes mounted, with the youngster committing his fourth double fault to lose the second game.

The American fell further behind before finally holding serve for 1-4 and launching a spirited rally, although one that came too late.

“I didn’t feel great during the match, I wasn’t moving my feet,” Tiafoe said. “He didn’t give me too many chances, I was leaving a lot of balls short.

“He took advantage, he could play like he wanted the entire match.”