(CNN)There may be a new tournament in men's tennis -- but the title will be decided by two of the game's longstanding legends.
Novak Djokovic and Rafael Nadal mustered all their experience to see Serbia and Spain through to the inaugural ATP Cup finals in Sydney, Australia.
The two tennis titans came through testing matches Saturday to once again inspire the hopes of their nations in the new team competition -- and set up their 55th meeting.
Djokovic muscled past Russia's Daniil Medvedev 6-1, 5-7, 6-4, in a match he described on ATPTour.com as "exciting, exhausting, joyful and dreadful all at once."
Athleticism is a big weapon for Djokovic and the 32-year-old needed to be at his physical best against the Russian world No.5, who faced off against Nadal in last year's U.S Open.
"It was a lot of rallies ... A very physical battle," added Djokovic.
With Dusan Lajovic already putting Serbia 1-0 up in their semi-final against Russia, victory for Djokovic sealed Serbia's place in the finals.