Alexander Zverev continued his dominant form since the summer, defeating Frances Tiafoe 7-5 6-4 in the final of the Vienna Open.
The 24-year-old Zverev of Germany edged out the 23-year-old American qualifier in two tight sets to claim his fifth tour-level title this season.
The pair traded breaks before Olympic champion Zverev broke down at the end of the first set to lead.
He pressured Tiafoe during the second set, breaking love to win.
Zverev has won all five finals he has played this season, also winning titles in Acapulco, the Madrid and Cincinnati Masters, and Olympic gold in Tokyo, losing just two games since the fourth round at Wimbledon.
The German has already qualified for the ATP Tour Finals, which he won in 2018, to be played in Turin.
In early October, the ATP announced that it was investigating allegations that Zverev was violent with an ex-girlfriend. Deny the accusations.
On the other hand, the former champion of the US Open of Croatia Marin cilic won his first hardcourt title since 2016, beating the United States Taylor fritz 7-6 (7-3) 4-6 6-4 in the final in St. Petersburg.
Donna Vekic, another Croat, beat up a Danish teenager Clara Tauson 7-6 (7-3) 6-2 at the Courmayeur Ladies Open to win her first title in more than four years.
At his home tournament in Romania, former world number one Simona halep lost to Estonia Anett Kontaveit 6-2 6-3, at the Transylvania Open.
The victory, along with her title in Moscow last week, secures a place for Kontaveit in the WTA Finals to be held in Guadalajara, Mexico, starting on November 10.