Rafael Nadal and Roger Federer last met in a grand slam final at the 2011 French Open but their rivalry at the highest level will resume in Melbourne on Sunday.
Ahead of their unexpected showdown for the Australian Open title, here Press Association Sport looks back at the rivalry.
The pair have 31 grand slam titles between them, with a record 17 won by Federer and Nadal tying for second on the all-time list after 14 triumphs. Federer, now 35, has landed four Australian Open crowns, also winning Wimbledon seven times, the US Open five times and the French Open once. Nadal was for many years unbeatable on the Paris clay, and has won the French Open a record nine times, the US Open and Wimbledon both twice and the Australian Open once.
From 2003 to 2014, Nadal and Federer picked up 31 of the available 48 grand slam men's singles titles. They are the only pair in the open era to have met eight times in grand slam finals, and they contested every French Open and Wimbledon final from 2006 to 2008. The development of Novak Djokovic and Andy Murray suggested the Nadal-Federer rivalry at the top of tennis had been overtaken, and yet in January 2017 here we are again.
The pair have faced each other 34 times and the head-to-head record is surprisingly one-sided, with Nadal leading 23-11. The Spaniard has also won nine of their 11 grand slam matches, including six of eight finals. Federer's grand slam wins over Nadal both came in Wimbledon finals, in 2006 and 2007. A year later Nadal had his revenge on the SW19 grass, winning arguably the greatest of Wimbledon finals.
The most recent match between the pair came in the Swiss Indoors final in November 2015. Federer ended a five-match winless run against Nadal as he defeated the Spaniard 6-3 5-7 6-3. It was the first time Federer had played Nadal with home advantage and he saw off his old nemesis to win the title for a seventh time.