Climate activists disrupt Italian Open tennis matches

Two protesters ran on to the court wearing orange vests and threw confetti, while other activists cemented their feet to the stands on Tuesday (AEST).

"As soon as I saw them come over the barrier, my first thought was like, 'Should I go tackle one of them?' But I stopped myself," Keys said.

"And then the chair (umpire) started yelling at me to go sit down.

"Unfortunately, it's starting to become a little bit of a common thing that's happening."

The players returned to the locker room and the protesters did not resist when security intervened before police and firefighters also arrived to handle the situation.

Keys was leading 6-2 3-1 when the match was temporarily suspended, with the players returning to the locker room. After play resumed, the 18th-seeded American went on to win the second set 6-1.

Keys will face top seed Iga Swiatek in the last eight after the world No.1's 7-5 6-3 victory over Angelique Kerber. It was a ninth straight win for the Pole, and the two-time Italian Open champion remains on course for an uncommon Madrid-Rome double.

Play was also interrupted by protesters on Court 12, where Santiago Gonzalez and Edouard Roger-Vasselin were playing a second-round doubles match against Marcelo Arevalo and Mate Pavic.

Elsewhere in the women's event, second seed Aryna Sabalenka saved three match points on her way to winning a thriller against Elina Svitolina 4-6 6-1 7-6 (9-7).

Sabalenka was treated for a back injury early in the final set but completed her comeback win and will next face former French Open champion Jelena Ostapenko, who also came from behind to beat Rebecca Sramkova 4-6 6-4 7-6 (7-3).

Victoria Azarenka upset world No.8 Maria Sakkari 6-4 6-1 and next plays 13th seed Danielle Collins, who coasted past Irina-Camelia Begu 6-0 6-3.

Naomi Osaka lost 6-2 6-3 to China's Zheng Qinwen. The Australian Open runner-up will next play Coco Gauff who beat Spain's Paula Badosa 5-7 6-4 6-1.

Australian Associated Press