Switzerland's Roger Federer beat John Isner of the United States to win the Miami Open ©Getty Images

Switzerland's Roger Federer swept aside defending champion John Isner of the United States to win his fourth Miami Open title.

The world number one beat Isner 6-1, 6-4 in one hour and three minutes at Hard Rock Stadium.

It was Federer's 50th Association of Tennis Professionals (ATP) Masters 1000 final and the 28th he had won. 

"What a week it's been for me," said Federer.

"I'm just so happy right now. 

"It's unbelievable – I played here in 1999 for the first time and here I am in 2019. 

"It means a lot to me."

Isner hurt his foot in the second set but continued to play. 

“Roger was too good," said Isner.

"In the first five games, I was fine and nothing was bothering me. 

"He was all over me. 

"Then this weird pain on the top of my foot. 

"I'm hoping it's nothing but we'll see.”

Australia's Ashleigh Barty had won the Women's Tennis Association Premier Mandatory title yesterday.