Federer was again unconvincing as he was forced to go the distance to beat Bautista Agut 6-3, 2-6, 6-4 to progress to the quarter-finals.

A day previous, the Swiss star also struggled to overcome Daniil Medvedev, needing all three sets once again.

But Bautista Agut, who has now lost all eight matches he has played against Federer, rued a crucial call from the umpire in the deciding set.

With the score at 4-4, the Spaniard struck a lovely shot which landed in, but the line judge called out and the point had to be replayed.

Had Bautista Agut won that point, he would likely have held serve, but instead, Federer broke and then served for the match.

“It is not the first time that favouritism has occurred,” Bautista Agut raged after the defeat.

“I do not think I lost by that ball, but in my opinion I do not think the referee was right there.

“I’m a bit disgusted with the result because I think I have made merits to win or to put myself in a position to win, it was the first time I had Federer on the ropes, it was a good day to beat him and in the end he was not able to win.

“It was a very tense moment, I went 30-0, with two good serves, I was 30 equal and I felt the tension of having Federer in front of me.

“That the match was at a very critical point, a decisive moment like that, in a deuce, a point more or a point less is decisive.”

However, Federer believes he upped his game when the stakes began to increase deep into the final set.

“I thought at 4-4 in the third set I was playing a good match,” Federer said.

“It was the same as yesterday.

“You might see negative bits because it’s so close and you’re so close from losing. But today I was more calm.

“Maybe I just had it in my racket somehow.

“It was just important for me to stay calm all the way through.”