It was a mixed day for the seeded players in action at the Open 13 on Thursday.
Milos Raonic or Philipp Kohlschreiber await Stan Wawrinka in the second round of the Rotterdam Open after he beat Benoit Paire.
Former world number four Tomas Berdych was won all but two of his 10 matches this season after returning from a back injury.
Nick Kyrgios described Milos Raonic's performance against him as "scary", while Novak Djokovic and Alexander Zverev eased into round two.
Defending champion Jo-Wilfried Tsonga ended an eight-month wait for a win in Antwerp and will now face compatriot Gael Monfils.
Alexander Zverev is closing in on an ATP Finals spot after winning in Shanghai, while Roger Federer also reached the third round.
Juan Martin del Potro will return to London for a first ATP Finals appearance in five years after reaching the last eight in Beijing.
Feliciano Lopez was on the brink of defeat in Beijing, but hung in there and went on to beat seventh seed Borna Coric.
French Open finalist Dominic Thiem has followed up making the last eight at the US Open by reaching the St Petersburg Open's quarter-finals.
Stan Wawrinka needed to win a pair of tie-breaks to beat Karen Khachanov in their round-of-16 match at the St Petersburg Open.