Croatia's Nikola Mektic (L) and Netherlands' Wesley Koolhof (2nd L) congratulate Poland's Lukas Kubot (2nd R) and Brazil's Marcelo Melo (R) after their men's doubles round-robin match on day five of the ATP World Tour Finals tennis tournament at the O2 Arena in London on November 19, 2020. (Photo by Glyn KIRK / AFP)