World number eight Alexander Zverev of Germany captured his fourth title of the year Sunday, defeating South Africa's Kevin Anderson 6-4, 6-4 in the ATP and WTA Citi Open men's final.
The 20-year-old from Hamburg dropped only nine points on his serve and never faced a break point in taking the $355,460 top prize at the US Open tuneup event on the Washington hardcourts.
Zverev, coming off a fourth-round Wimbledon run that was his best Grand Slam result, also won titles this year at Montpellier, Munich and Rome after claiming his first ATP crown last September at St. Petersburg.
Zverev thanked new co-coach Juan Carlos Ferrero, the former world number one from Spain who worked with him at an event for the first time this week.
"Thanks for joining this crazy team," Zverev said. "What a way to start together and hopefully we have many more years to come and many more titles together."
Ferrero was asked to join Zverev's father, Alex Snr, in guiding the prodigy in May.
"It's amazing what we've already accomplished," Zverev said. "Hopefully a lot more will come in the future."
Zverev, who will remain a career-best eighth in next week's rankings, took the only break of the first set in the third game.
Anderson rescued break points with an ace and a service winner but netted a forehand overhead smash to drop the game.
Zverev broke to open the second set and held serve from there for the championship, ending matters after 69 minutes when Anderson swatted a backhand wide and raising his arms in the air in celebration.
Only Rafael Nadal has reached more ATP finals this year than the five of Zverev, whose only championship match loss came to Roger Federer at Halle in June.
Anderson, in his first ATP final since winning the 2015 Winston-Salem title, fell to 0-3 lifetime against Zverev, having lost a 2015 Washington second-round match and a first-round meeting in May on clay in Rome.
Anderson, ranked 45th, will jump to 33rd in next week's rankings, his best mark since he was 25th last August.
The lanky 31-year-old from Johannesburg missed out on his fourth career title after Winston-Salem, Delray Beach in 2012 and his hometown in 2011.
In the later women's final, Russia's 58th-ranked Ekaterina Makarova was set to face Germany's 40th-ranked Julia Goerges with each seeking her third career WTA crown and a $43,000 top prize.
Makarova, being coached by Britain's Nigel Sears, is in her first final since winning the title in 2014 at Pattaya City. Her first WTA crown came at Eastbourne in 2010.
Goerges, a winner in 2011 at Stuttgart and 2010 at Bad Gastein, was a runner-up earlier this year at Mallorca. She lost her only prior meeting with Makarova in the fourth round of the 2015 Australian Open.