Great Britain's Andy Murray has acknowledged that his four-set victory over Juan Martin del Potro in the Olympic final was one of the most exhausting of his career.

Murray needed four hours and two minutes to see off the Argentine in front of a partisan South American crowd, and the British number one has admitted that the match - which he won by a 7-5 4-6 6-2 7-5 scoreline - has left him feeling drained ahead of his return to the ATP Tour next week.

The 29-year-old told BBC Sport: "Tonight is one of the toughest matches I've had to play for a big title.

"The US Open for my first slam was hard. Physically there were so many ups and downs in the match. It was one of the toughest I've played for sure.

"Anything could have happened. This one means a lot but I won't get the chance to enjoy it as much as I'm playing a match in 48 hours."

Murray is scheduled to face either Ivo Karlovic or Juan Monaco in the second round of the Cincinnati Open on Wednesday.