The world No 15 Croatian lived up to her senior status in the first set but could not maintain the momentum as Cornet fought back to win 3-6, 6-4, 6-4, sealing the outcome with three aces back-to-back in the final game.

“What a match,” Cornet, who is ranked 57th, said as she left the court.

Cornet switched coaches to Martic’s former mentor Sandra Zanieswka during the off-season and said she initially had trouble adjusting to her new pre-match instructions to be aggressive.

“It was going out of my comfort zone and in the first set I didn’t manage to do it but finally I found my rhythm and was playing much better,” she said with her only three aces coming when she was down 15-30 in the final game.

“Thank God my serve helped me.”

Cornet, who also rallied from a set down to win her first-round match against Ysaline Bonaventure, will meet Jessica Pegula in the quarterfinals after the American had a comfortable 6-2, 6-2 second-round win over Tamara Zidansek.

Caroline Garcia became the second seed to fall when the eighth-seed from France was beaten by Canada’s Eugenie Bouchard.

Both are former top-five stars with Bouchard, the Wimbledon finalist in 2014, now as low as 262 in the world while Garcia is ranked 46th.

In the quarterfinals, Bouchard will play the winner of the second-round match between third-seed Amanda Anisimova and former top-10 player Daria Kasatkina of Russia.