Toronto - Stanislas Wawrinka had to pass a stern test lasting two hours before emerging with a 7-6 (7/3), 7-6 (10/8) victory over Mikhail Youzhny for a third-round berth at the Toronto Masters.
The second-seeded two-time Grand Slam champion was joined in the third round on Tuesday by fifth-seeded Czech Tomas Berdych, who dispatched Croatian Borna Coric 4-6, 6-1, 6-4 in the only other second-round match of the day.
Berdych was caught on the back foot in his opening set against Coric, with the Croatian losing a mere four points on serve.
But Berdych found his game in the second set, winning five straight games to squeeze into a deciding third set where he prevailed.
Wawrinka and savvy 34-year-old Youzhny last played in 2010, with the Russian winning their last two meetings from a set down at Miami and the US Open.
Youzhny again proved to be a tough customer, missing a chance to take the contest to a third set but forcing Wawrinka into errors on two match points before the Swiss put it away on this third.
In first-round action, Gael Monfils followed up his first tournament title in more than two years by barrelling through to victory.
The flamboyant Frenchman, seeded 10th and fresh off his triumph in Washington, defeated Portugal's Joao Sousa 6-3, 6-3.
He's hoping this week to improve on his best Canadian result, a quarter-final run in 2011.
Monfils, who defeated big-serving Croatian Ivo Karlovic in the final in Washington on Sunday, said conditions are changed in Toronto.
"I think the court is slower here. It's for sure less humidity and a little bit colder," he said. "The balls are flying more. It's quite a big change, actually."
Monfils notched his 30th match win of the season to open his campaign at the tournament that is the last before the Rio Olympics.
The often-injured Monfils said that he had just heard the news that Roger Federer's 2016 season was over, as the Swiss great will miss Rio and the US Open rehabbing a knee injury.
"We all have these (injuries)," Monfils said. "For sure we use our knee very, very, very much. Every surface, every court."
French 13th seed Lucas Pouille joined Monfils in advancing as he beat Emilio Gomez of Ecuador 6-7 (8/10), 6-4, 7-5. Veteran Czech qualifier Radek Stepanek knocked out French 14th seed Benoit Paire 6-1, 6-3 to book a date with Canadian wild card Peter Polansky.
Taiwan's Lu Yen-Hsun beat Alexander Zverev, a Washington semi-finalist, 7-5, 6-3.
A freshly shaven-headed Fabio Fognini dismissed 15th seed Steve Johnson 6-4, 6-4 while Canadian Vasek Pospisil earned a home win as 2015 French semi-finalist Jeremy Chardy was forced to retire trailing 7-6 (7/3).
Karlovic gave away nearly two decades to Taylor Fritz but the 37-year-old Croatian beat the teenager 6-7 (9/11), 7-6 (7/5), 6-2.
Lu will next take on Canadian fourth seed and Wimbledon finalist Milos Raonic, the 2013 finalist who lost his opening match at home a year ago.
"If a 10 000 crowd is against you, even if you prepare for it, it's still a shock," said Lu of his likely Raonic scenario.
"I'll be a little bit nervous, I hope I can play my best tennis and try to enjoy the 10 000 people against me!"
The top eight seeds enjoy first-round byes. World number one Novak Djokovic is due to launch his campaign on Wednesday against Gilles Muller.
Results on Tuesday in the Toronto ATP Masters hardcourt tennis tournament (x-denotes seeded player):
Tomas Berdych (CZE x5) bt Borna Coric (CRO) 4-6, 6-1, 6-4
Stanislas Wawrinka (SUI x2) bt Mikhail Youzhny (RUS) 7-6 (7/3), 7-6 (10/8)
Radek Stepanek (CZE) bt Benot Paire (FRA x14) 6-1, 6-3
Lu Yen-Hsun (TPE) bt Alexander Zverev (GER) 7-5, 6-3
Jared Donaldson (USA) bt John Millman (AUS) 6-4, 4-3 retired
Fabio Fognini (ITA) bt Steve Johnson (USA x15) 6-4, 6-4
Gael Monfils (FRA x10) bt Joao Sousa (POR) 6-3, 6-3
Vasek Pospisil (CAN) bt Jrmy Chardy (FRA) 7-6 (7/3), retired
Ivo Karlovic (CRO) bt Taylor Fritz (USA) 6-7 (9/11), 7-6 (7/5), 6-2
Lucas Pouille (FRA x13) bt Emilio Gomez (ECU) 6-7 (8/10), 6-4, 7-5
Rajeev Ram (USA) bt Ernests Gulbis (LAT) 6-4, 6-2
Dennis Novikov (USA) bt Federico Del Bonis (ARG) 6-4, 6-3
Donald Young (USA) bt Alexandr Dolgopolov (UKR) 7-6 (8/6), 6-4