Venus Williams lost to fellow American Madison Keys, falling 6-2, 7-5 in the opening round of the National Bank Open here.

The 43-year-old Venus, a seven-time grand slam champion, dropped to 2-4 in six career matches against the 28-year-old Keys.

The 16th-ranked Keys broke Venus twice in the first set. She recorded two more breaks in the second and held on for the win.

Keys, who is also playing with fellow American Jennifer Brady in the women’s doubles tournament, now faces Italian Jasmine Paolini in the round of 32.

Czech Republic’s Karolina Pliskova posted a 6-3, 6-7 (8-10), 6-2 win over China’s Lin Zhu in the opening round.

Pliskova, ranked No. 23 in the world, had 11 aces and seven double-faults. She converted five of 16 break points.

Zhu had two aces and eight double-faults. She broke on two of her three opportunities.

It was one of just three women’s singles matches on Monday to reach the finish line as play was temporarily suspended due to rain.

Former world No.1 Victoria Azarenka brushed aside long rain delays to advance.

In the first match on centre court, Azarenka and Magda Linette twice had play halted before the 16th-seeded Belarusian finally prevailed 6-3, 6-0 in a contest that took nearly five hours to complete.

Azarenka was unfazed by the rain, charging ahead 5-2 in the opening set before closing it out with a break just before play was stopped a second time. Returning to the court three hours later, Azarenka was taking no chances of another delay. She romped through the second set, winning 24 of 31 points and breaking Poland’s Linette three times.

Spaniard Paula Badosa announced her withdrawal from the tournament.

AP/PTI