2018 Nitto ATP FINALS Marin Cilic (CRO) defeated John Isner (USA) 67(2) 63 64 Photo © Ray Giubilo This image may not be reproduced or sold to third parties.

2018 Nitto ATP FINALS Marin Cilic (CRO) defeated John Isner (USA) 67(2) 63 64 Photo © Ray Giubilo This image may not be reproduced or sold to third parties.

2018 Nitto ATP FINALS FINAL Practice session. Novak Djokovic (SRB) Photo © Ray Giubilo This image may not be reproduced or sold to third parties.

2018 Nitto ATP FINALS FINAL Practice session. Novak Djokovic (SRB) Photo © Ray Giubilo This image may not be reproduced or sold to third parties.

2018 Nitto ATP FINALS FINAL Practice session. Alexander Zverev (GER) and Ivan Lendl (USA) Photo © Ray Giubilo This image may not be reproduced or sold to third parties.

2018 Nitto ATP FINALS FINAL Practice session. Alexander Zverev (GER) and Ivan Lendl (USA) Photo © Ray Giubilo This image may not be reproduced or sold to third parties.

2018 Nitto ATP FINALS FINAL Practice session. Alexander Zverev (GER) and Ivan Lendl (USA) Photo © Ray Giubilo This image may not be reproduced or sold to third parties.

2018 Nitto ATP FINALS FINAL Practice session. Alexander Zverev (GER) and Ivan Lendl (USA) Photo © Ray Giubilo This image may not be reproduced or sold to third parties.

2018 Nitto ATP FINALS FINAL Alexander Zverev (GER) defeated Novak Djokovic (SRB) 64 63 Photo © Ray Giubilo This image may not be reproduced or sold to third parties.

2018 Nitto ATP FINALS Roger Federer (SUI) defeated Kevin Anderson (RSA) 64 63 Photo © Ray Giubilo This image may not be reproduced or sold to third parties.

2018 Nitto ATP FINALS Roger Federer (SUI) defeated Kevin Anderson (RSA) 64 63 Photo © Ray Giubilo This image may not be reproduced or sold to third parties.

2018 Nitto ATP FINALS Novak Djokovic (SRB) defeated Alexander Zverev (GER) 64 61 Photo © Ray Giubilo This image may not be reproduced or sold to third parties.

2018 Nitto ATP FINALS O2 ARENA Photo © Ray Giubilo This image may not be reproduced or sold to third parties.