Novak Djokovic continued his quest to lead the world tennis rankings with a 7-5, 6-1 victory over Joao Sosa in the second round of the Paris Masters.
Goku, the world number two, who did not play in the first round, broke his opponent four times to make it 19 straight.
The 31-year-old has regained his top spot this season, winning the Wimbledon and American Open titles, as well as the Masters in Cincinnati and Shanghai.
Djokovic in Paris needs a better result than world number one Rafael Nadal to take off the summit when the new rating is announced next Monday.
If both players play the same role, Nadal will remain at the top of the world rankings before the final of the season in London next month.
Milos Runic, Canada, 6-7, 7-6 (7-6), 7-6 (6), beat Frenchman Jo-Wilfried Tsonga to qualify for the second round.
In a match between players who had already reached the final, Runic hit 23 straight shots to beat Tsonga in less than three hours.
The 27-year-old will play in the next game with veteran Roger Federer, who is looking for his 100th career title.
Fernando Verdasco made a strong offer to beat Frenchman Jeremy Chardy 6-4, 6-4 to qualify for Nadal in the second round on Wednesday.
