Rotterdam - Grigor Dimitrov and David Goffin, the duo who faced off in last year's season-ending ATP Finals, both advanced at the Rotterdam Open on Wednesday with straight-sets wins.
Second seed Dimitrov, who beat Belgian fourth seed Goffin in the London final last November, had to fight back in the second set to defeat Japan's Yuichi Sugita 6-4, 7-6 (7/5) in their first-round encounter.
Goffin made light work of veteran Spaniard Feliciano Lopez, cruising through 6-1, 6-3 to reach the quarter-finals in his second match of the week.
Dimitrov won the opening set against Sugita but fell behind a break in the second before levelling for 5-all.
As the set went into a tie-break, the Bulgarian surged ahead as he took a 5-2 lead but had to hold off his opponent as Sugita clawed back to within a point of levelling.
But Dimitrov then sent a forehand into the corner to earn a pair of match points and advanced on his second with a service winner to end the resistance of the 41st-ranked Sugita.
Last week's Montpellier champion Lucas Pouille exited in his opening match, losing 7-5, 6-4 to Andrey Rublev.
The Russian was joined in the second round at the Ahoy Arena by Pierre-Hugues Herbert of France, who advanced after just 15 minutes when compatriot Richard Gasquet, the Montpellier finalist, retired with a groin injury trailing 3-1.
Top seed Roger Federer is expected on court later on Wednesday as he launches his bid for a return to the world's No 1 ranking against Belgian Ruben Bemelmans in a first-time meeting.
The 36-year-old Federer could become the oldest man by three years to hold the number one spot if he reaches the semi-finals at an event he has won twice.
Pouille lost in 93 minutes, hitting a dozen aces in defeat but losing serve four times.
The 34th-ranked Rublev owns his only career title from Umag last summer on clay. Herbert will play Russian Daniil Medvedev in the second round.
Robin Haase won an all-Dutch affair over Thiemo de Bakker 6-2, 6-2.
Results from the third day of the ATP Rotterdam World Tennis tournament on Wednesday (x denotes seeding):
David Goffin (BEL x4) bt Feliciano Lopez (ESP) 6-1, 6-3
Robin Haase (NED) bt Thiemo de Bakker (NED) 6-2, 6-2
Pierre-Hugues Herbert (FRA) bt Richard Gasquet (FRA) 3-1, retired
Andrey Rublev (RUS) bt Lucas Pouille (FRA x7) 7-5, 6-4
Damir Dzumhur (BIH) bt Marius Copil (ROM) 6-4, 6-4
Grigor Dimitrov (BUL x2) bt Yuichi Sugita (JPN) 6-4, 7-6 (7/5)