Washington - Reigning US Open champion Marin Cilic and runner-up Kei Nishikori advanced to the third round of the ATP and WTA Washington Open in hard-fought matches that finished early Wednesday morning.
Japan's fifth-ranked Nishikori rallied to beat Australian James Duckworth 6-7 (8/10), 6-1, 6-4 while Croatia's eighth-ranked Cilic defeated 77th-ranked South Korean teen Chung Hyeon 7-6 (7/2), 6-3 in their first hardcourt appearances on the road to this year's US Open.
"It wasn't easy to put him away," Cilic said. "He's a great counterpuncher."
Cilic, the first reigning US Open champion to play in the US capital since Andre Agassi in 2000, and second seed Nishikori each had first round byes and saw their matches pushed into the wee hours by a rain delay.
"It gives me more confidence," Cilic said of his Grand Slam title.
"I'm sure it's going to give me more faith in my game. In this moment I'm very happy with my game."
Next in Nishikori's path will be the winner of a Wednesday match between Argentina's Leonardo Mayer and Slovenia's Blaz Rola.
The 25-year-old Asian number one, playing his first match since pulling out of Wimbledon in the second round with a calf injury, fought back after dropping a tense tie-breaker to seize command of the match.
"From the second set I started playing better, less unforced errors, more aggressive," Nishikori said.
"I was happy with how I played after the first set."
In his first match since a Wimbledon quarter-final loss to eventual champion Novak Djokovic, Cilic surrendered a break in the seventh game but broke back in the eighth.
In the tie-breaker, Cilic jumped ahead 6-1, double faulted, then blasted a service winner to win the set after 53 minutes, taking all 18 of his first serve points in the set.
"The important part was to get the ball back and put the first serve away," Cilic said.
Third seed Cilic opened the second set with a break and broke again for a 4-1 edge before Chung broke back and held to restore some pressure.
Chung had two break-point chances on Cilic in the eighth game but the veteran saved them on a net cord winner and his ninth ace and held, then broke to claim the victory.
Cilic booked a third-round meeting with American Sam Querrey, who fired 26 aces to oust Japan's Go Soeda 6-3, 5-7, 6-4.
Nishikori, tested by a 23-year-old rival ranked 90 spots below him in his pre-Open hardcourt opener, seeks his third title of the year after Memphis and Barcelona and his 10th career crown.
"It was my first match on hardcourt," said Nishikori. "It had been a long time since I played on hardcourt. This should be OK for the next match."
Duckworth grabbed a 6-4 tie-breaker lead after Nishikori sent a backhand wide. Nishikori saved two set points before the Aussie followed with his eighth ace, but he then hit a backhand long to fall level at 7-7.
Nishikori's third ace brought his first set point but Duckworth rescued that with a service winner wide, then hit another and finally took the set on his fourth chance when Nishikori sent a backhand volley beyond the baseline.
In the second set, it took Nishikori five break-point chances but he finally bested Duckworth for a 2-0 lead and he rolled from there, then broke Duckworth for a 2-1 edge in the third set and held serve to the end.
In women's first-round matches, Russian top seed Ekaterina Makarova downed Belgium's Alison Van Uytvanck 7-5, 7-5 and Aussie second seed Samantha Stosur, the 2011 US Open champion, defeated France's Kristina Mladenovic 6-2, 6-2 for her 500th career match victory.
Results on Tuesday from the second day of the ATP and WTA Washington Open (x denotes seeding):
Sam Querrey (USA) bt Go Soeda (JPN) 6-3, 5-7, 6-4
Jack Sock (USA) bt Ruben Bemelmans (BEL) 7-6 (9/7), 6-3
Vasek Pospisil (CAN) bt Donald Young (USA) 7-5, 6-3
Kei Nishikori (JPN x2) bt James Duckworth (AUS) 6-7 (8/10), 6-1, 6-4
Marin Cilic (CRO x3) bt Chung Hyeon (KOR) 7-6 (7/2), 6-3
Steve Johnson (USA) bt Lukas Lacko (SVK) 7-5, 6-3
Sam Groth (AUS) bt Thomaz Bellucci (BRA) 7-6 (10/8), 4-6, 6-3
Lleyton Hewitt (AUS) bt John-Patrick Smith (AUS) 6-3, 6-4
Blaz Rola (SLO) bt Denis Kudla (USA) 2-6, 6-4, 7-6 (7/5)
Guido Pella (ARG) bt Ivan Dodig (CRO) 6-3, 6-7 (7/9), 7-5
Alexandr Dolgopolov (UKR) bt Tim Smyczek (USA) 6-4, 6-2
Gilles Muller (LUX) bt Malek Jaziri (TUN) 6-3, 7-5
Samantha Stosur (AUS x2) bt Kristina Mladenovic (FRA) 6-2, 6-2
Christina McHale (USA) bt CoCo Vandeweghe (USA x7) 6-2, 4-6, 6-4
Polona Hercog (SLO) bt Julia Glushko (ISR) 6-2, 7-5
Ekaterina Makarova (RUS x1) bt Alison Van Uytvanck (BEL) 7-5, 7-5
Naomi Broady (GBR) bt Jarmila Gajdosova (AUS) 3-6, 7-5, 7-6 (8/6)
Belinda Bencic (SUI x3) bt Tereza Smitkova (CZE) 7-5, 6-4
Sloane Stephens (USA) bt Magda Linette (POL) 6-2, 6-1
Svetlana Kuznetsova (RUS x4) bt Sanaz Marand (USA) 6-2, 6-4
Anastasia Pavlyuchenkova (RUS) bt Magdalena Rybarikova (SVK) 7-6 (7/2), 7-6 (7/3)