Venus Williams falls in WTA Finals opener

Third-seeded Karolina Pliskova cruised to a 6-2, 6-2 win over fifth-seeded Venus Williams on the opening day of the WTA Finals in Singapore.

In Sunday’s other match at the round-robin event, second-seeded Garbine Muguruza of Spain (1-0) posted a 6-3, 6-4 win over seventh-seeded Jelena Ostapenko of Latvia (0-1).

Ostapenko, who won her first career title at this year’s French Open, is making her debut at the year-end event.

Stockholm Open: Argentina’s Juan Martin del Potro won his 20th career title, beating Grigor Dimitrov of Bulgaria in a successful title defense at Stockholm.

Del Potro held serve throughout as he won 6-4, 6-2 against Dimitrov while also landing 70 percent of first serves and firing in nine aces.

It was the Argentine’s first title since he beat Jack Sock in last year’s Stockholm final. The two Stockholm wins are del Potro’s only tour titles since he returned in 2016 following chronic wrist problems.

For Dimitrov, it was his fourth final of the year and first defeat. The Bulgarian is now 7-6 in career finals.

Kremlin Cup: Damir Dzumhur recovered from a second-set slip to beat Ricardas Berankis and win in Moscow.

Bosnia’s Dzumhur beat his Lithuanian opponent 6-2, 1-6, 6-4 to win his second career ATP title after victory last month at the St. Petersburg Open.