Cape Town - Novak Djokovic broke off from serving for victory against Portugal' Joao Sousa to help a spectator who was taken ill at the Paris Masters on Tuesday.
According to the BBC website, the match came to a stop as the spectator was attended to, with Djokovic providing him with a towel before he left his seat for treatment.
The Serbian world No 2 was nearly broken when play resumed, but served out for the match to win 7-5, 6-1.
Djokovic will play Bosnian Damir Dzumhur in the third round.
Meanwhile, world No 1 Rafael Nadal and No 3 Roger Federer will start their campaigns at the tournament on Wednesday.
Nadal will play fellow Spaniard Fernando Verdasco, while Federer faces Milos Raonic of Canada.
Results from the ATP Paris Masters on Tuesday (x denotes seeding):
Novak Djokovic (SRB x2) bt Joao Sousa (POR) 7-5, 6-1
Marin Cilic (CRO x5) bt Philipp Kohlschreiber (GER) 6-3, 6-4
Karen Khachanov (RUS) bt Matthew Ebden (AUS) 6-2, 2-0 retired
Damir Dzumhur (BIH) bt Stefanos Tsitsipas (GRE x14) 6-3, 6-3
Fernando Verdasco (ESP) bt Jeremy Chardy (FRA) 6-4, 6-4
Daniil Medvedev (RUS) bt Pablo Carreno Busta (ESP) 6-2, 6-2
Gilles Simon (FRA) bt Lucas Pouille (FRA) 6-3, 6-4
Mikhail Kukushkin (KAZ) bt Pierre-Hugues Herbert (FRA) 3-6, 6-3, 7-5
Marton Fucsovics (HUN) bt Benoit Paire (FRA) 6-4, 6-4
Milos Raonic (CAN) bt Jo-Wilfried Tsonga (FRA) 6-7 (4/7), 7-6 (7/5), 7-6 (7/5)