WASHINGTON: Japan’s seventh-ranked Kei Nishikori captured his fourth consecutive ATP Memphis Open title on Sunday by defeating 18-year-old US wildcard Taylor Fritz 6-4, 6-4.

Top seed Nishikori won his 11th career ATP crown by taking his 17th consecutive Memphis match victory.

He joins Roger Federer, Novak Djokovic and Rafael Nadal as the only active players to have won the same event four years in a row.

“It has been amazing,” Nishikori said as he accepted the guitar-shaped champion’s trophy. “It was really fun on the court. This is something I’ve never done before, something new. I’m very happy for that.”

Fritz, in only his third tour-level event, was the youngest American in an ATP final since a 17-year-old Michael Chang won at Wembley in 1989.

“It was a great week for me,” Fritz said. “Winning the tournament four times, that’s incredible. He was too tough for me today.”

Fritz smashed a backhand winner down the line to break Nishikori’s first service game of the match — his lone break of the contest — and then held at love himself for a 3-0 edge. But the Asian ace bounced back by winning six of the next seven games.

A double fault cost Fritz a break in the fifth game and he struggled to hold in the seventh, denying Nishikori break points on two aces and a service winner. Nishikori broke in the ninth game on a forehand winner and held at love to claim the first set after 36 minutes.

In the second set, Nishikori broke on a forehand winner for a 3-2 lead and forced Fritz to save two match points in the ninth game before holding in the 10th on a forehand winner to end it after 79 minutes.

After starting the week 1-2 in ATP play, Fritz will jump from 145th to 103rd in the world rankings.

“I’m sure he has got a bright future and is going to be among the top players very soon,” Nishikori said of Fritz.

Fritz, last year’s US Open junior champion, made his ATP debut last year at Nottingham, beating Carreno Busta before a second-round exit. He lost to compatriot Jack Sock in five sets in the first round of last month’s Australian Open.

Thiem triumphs

In Buenos Aires, Austria’s Dominic Thiem backed-up his shock semifinal win over Rafael Nadal to clinch the Argentina Open title on Sunday with a 7-6 (7/2), 3-6, 7-6 (7/4) victory over Nicolas Almagro

Thiem, the world number 19 and the youngest player in the top 20, captured his fourth career title all of which have been on clay.

The 22-year-old claimed trophies on the surface at Gstaad, Umag and Nice, all in 2015.

Thiem had made the final by seeing off Nadal 6-4, 4-6, 7-6 (7/4) on Saturday, saving a match point in the process.

Almagro, 30, was the champion in Buenos Aires in 2011.

Petkovic back on track

In Dubai, Andrea Petkovic broke six times to start her week at the Dubai Tennis Championships on Monday with a 6-2, 6-1 defeat of Italian Camila Giorgi as the German winner ended a two-match loss streak.

The No. 26, who exited in the Australian Open first round after playing a Brisbane quarter-final and then was beaten in the Fed Cup by Swiss Belinda Bencic, is working with a new coaching team and feels her tennis has turned a corner after she toyed last December of quitting the sport.

Petkovic could face new world number nine Bencic in the next round at the Aviation Club if the weekend finalist in St. Petersburg beats former number one Jelena Jankovic in the opening round.

The 40th-ranked Giorgi saved two match points in the final game as Petkovic closed out the victory in 63 minutes with 15 unforced errors to the 33 of her opponent.

“I’m very happy with how I played, I’ve worked hard over the past few weeks to be ready here and I was able to translate good training onto the match court,” Petkovic said.

“All the work paid off, things are coming together for me.”

Petkovic said she had a close call after the end of last season, as she pondered her future in the game. “I was in New York and thought about just staying there. But in the end I took my plane to Germany and began to work on my game,” she said.

“I’m happy I made the right decision to stay in tennis.”

American Madison Brengle erased a 4-0 deficit in the second set to advance over Russian Ekaterina Makarova 6-4, 7-5.

The WTA field is headed by Romanian Simona Halep, with Spain’s Wimbledon finalist Gabriela Muguruza the second seed. The leading four seeds do not start until the second round thanks to byes.