"I haven't felt it in matches in a long time" - Taylor Fritz on "strange" injury experienced in Acapulco win over John Isner

American tennis star Taylor Fritz revealed he battled "a really strange injury" at the start of his Abierto Mexicano Acapulco match against John Isner on Monday.

Fritz, who achieved a career-high ranking of No 5 this Monday, came from a set down to beat compatriot John Isner 3-6 6-3 6-4 in his first match as a top-5 player. Fritz appeared to be dealing with a knee injury in the first set but looked better as the match progressed.

"It was really strange. It’s something that I’ve dealt with when I was 18," revealed the 25-year old. "Typically I only feel it when I’m getting off a flight or I haven’t played in a few days and I’m stiff. So I don’t know why I felt it like that. I haven’t felt it in matches in a long time. But once I started feeling better I started to play well.

"I thought I played really well in the third. I’m extremely happy. When the draw comes out, (Isner) is not what you want to see in the first round. It’s a 50/50 match; it can go either way. I was lucky to get through."