The ATP world tour finals title and the number one spot are on the line, when Andy Murray faces Novak Djokovic on Sunday.
This will be the 35th time the duo are going against each other, and the first time the number one ranking is at stake.
Murray overtook the Serb as number one earlier this month, and is currently on a 23-match winning streak. Djokovic is prepared to win back his spot.
“I’m really privileged to be a part of history on Sunday,” said the Serb.
Djokovic has won the last four titles in London and will overtake Murray with another win.
He added: “We’ve known each other for so many years. This is maybe one of the biggest matches we will ever play, so let’s enjoy it.”
Murray said: “Sunday is the last day for a while, we get a break after that. I’ll just give my best of what I’ve got. Hopefully it’s enough.”