Briton Emma Raducanu is through to round three at Indian Wells after opponent Dayana Yastremska retired with an injury in the opening set.
Raducanu, 21, raced into a 4-0 lead in just 18 minutes during the first set.
Ukrainian Yastremska stepped to the back of the court between games, holding her stomach before retiring from the contest after being assessed by the medics.
Raducanu will face Peyton Stearns or Aryna Sabalenka in round three.
Wild card Raducanu broke Yastremska’s serve in the opening game with a well-placed dropped shot and then dug in to save a break point during her first service game.
A strong backhand sealed a second break before Raducanu comfortably held in the fourth game.
Yastremska also retired with an injury during her only other meeting with Raducanu at Portoroz in Slovenia in 2022.
It is the first time Raducanu has registered successive victories since she won three in a row to reach the fourth round at Indian Wells in March 2023.
