Washington - World No 8 Alexander Zverev made a narrow escape while 10th-ranked Milos Raonic battled through two tie-breakers on Wednesday as both favourites reached the third round of the ATP and WTA Citi Open.
Zverev, a 20-year-old German seeking his fourth ATP crown of the year, rallied to oust Australia's 75th-ranked Jordan Thompson 4-6, 6-3, 7-6 (7/5).
"I'm just happy to be through and happy to get the win," Zverev said.
Canada's Raonic, hoping to end an 18-month ATP title drought, blasted 26 aces in defeating France's Nicolas Mahut 7-6 (7/2), 7-6 (10/8) on the Washington hardcourts where he won his biggest career title in 2014.
"This is a chance to really get things going the right way," Raonic said. "It's the leadoff to having a chance to turn things around. This year, I haven't had that good a season."
Zverev, who had not played a hardcourt match in four months, will seek his 100th career ATP match victory on Thursday against American Tennys Sandgren, who advanced after 10th-seeded Australian Nick Kyrgios retired trailing 6-3, 3-0 in their match.
Thompson, who upset Britain's top-ranked Andy Murray in the first round at Queen's, was poised to dump Zverev as well, taking the first set and grabbing a 5-4 edge in the deciding tie-breaker.
But the 23-year-old Aussie netted a backhand, then hit his only double fault of the match and swatted a forehand into the net to hand Zverev the victory after two hours and 11 minutes.
"I tried to stay calm, stay composed and focused on me," Zverev said. "He's playing very well right now."
Fifth seed Zverev, who jumped into his career-high ranking this week, has won titles at Montpellier, Munich and Rome this season, downing Novak Djokovic in the Italy final for the biggest win of his career.
"I worked a lot last year on my serve," Zverev said. "All of it is coming together, all the work I'm doing in the off-season. The little things are coming together."
Raonic advanced to a third-round match against Cypriot Marcos Baghdatis, who ousted US 16th seed Ryan Harrison 6-4, 6-1.
Raonic, 26, has not won an ATP title since last year at Brisbane, a run of 29 events. He has dropped five finals since then, including last year at Wimbledon.
Raonic was nagged by a right leg injury that forced him to withdraw from three events and surrender walkovers in two others, including the Delray Beach final.
"Until the recent weeks, my mind hasn't been on tennis as much," Raonic said, citing the injury and trying to play his best while not back in prime shape.
"Now is the first time I've had time to put all the pieces together and focus on my game."
Mahut, the oldest man in the draw at 35, was denied on two set points in the final tie-breaker, then sent a backhand crosscourt volley wide before a Raonic service winner ended matters.
South African 15th seed Kevin Anderson beat Tunisia's Malek Jaziri 6-4, 6-1 to book a third-round date on Thursday with Austrian top seed Dominic Thiem, who lost to Anderson in all five prior meetings, all on hardcourts.
The first men's upset came as 225th-ranked American Tommy Paul ousted French seventh seed Lucas Pouille 7-6 (8/6), 6-3. Paul next faces 11th seed Gilles Muller of Luxembourg.
On the women's side, 2014 Wimbledon runner-up Eugenie Bouchard of Canada upset US eighth seed Christina McHale 7-6 (8/6), 6-0. Bouchard visited Andre Agassi in Las Vegas for some help with her game.
"It's top secret stuff," she said. "Yes, I got lots of pointers."
French second seed Kristina Mladenovic outlasted Germany's Tatjana Maria 7-5, 3-6, 6-3. Mladenovic, who won her only WTA title in February at St. Petersburg, could meet Bouchard in the quarter-finals.
"Nothing has changed for me," Mladenovic said. "I'm just working on elevating my game and playing hard."
Results on Wednesday from the third day of the ATP and WTA Citi Open (x denotes seeding):
Jared Donaldson (USA) bt Marc Polmans (AUS) 6-2, 6-3
Milos Raonic (CAN x3) bt Nicolas Mahut (FRA) 7-6 (7/2), 7-6 (10/8)
Tommy Paul (USA) bt Lucas Pouille (FRA x7) 7-6 (8/6), 6-3
Gilles Muller (LUX x11) bt Dmitry Tursunov (RUS) 6-1, 6-2
Marcos Baghdatis (CYP) bt Ryan Harrison (USA x16) 6-4, 6-1
Kevin Anderson (RSA x15) bt Malek Jaziri (TUN) 6-4, 6-1
Alexander Zverev (GER x5) bt Jordan Thompson (AUS) 4-6, 6-3, 7-6 (7/5)
Grigor Dimitrov (BUL x4) bt Kyle Edmund (GBR) 7-5, 4-6, 6-3
Yuki Bhambri (IND) bt Gael Monfils (FRA x6) 6-3, 4-6, 7-5
Tennys Sandgren (USA) bt Nick Kyrgios (AUS x10) 6-3, 3-0 (retired)
Oceane Dodin (FRA x5) bt Sara Errani (ITA) 3-6, 7-5, 6-1
Ekaterina Makarova (RUS x7) bt Monica Puig (PUR) 6-2, 6-4
Eugenie Bouchard (CAN) bt Christina McHale (USA x8) 7-6 (8/6), 6-0
Sabine Lisicki (GER) bt Valentini Grammatikopoulou (GRE) 7-6 (9/7), 7-6 (7/5)
Monica Niculescu (ROM x6) bt Nao Hibino (JPN) 6-3, 2-6, 7-6 (9/7)
Kristina Mladenovic (FRA x2) bt Tatjana Maria (GER) 7-5, 3-6, 6-3