Sara Errani of Italy advanced to the semifinals with a 4-6, 6-1, 6-4 win over Madison Brengle of the U.S. at the Dubai Tennis Championships on Thursday.
Brengle, leading 4-1 in the third set, called her coach, former French player Julie Coin, to the court during the changeover. Brengle fell apart from that point on, losing the next five games and the match.
"It was a really strange match," Errani said. "I could've lost easily."
Errani will play the winner of the quarterfinal between CoCo Vandeweghe of the U.S. and Elina Svitolina of Ukraine.
Earlier, Caroline Garcia of France reached the semifinals with a 6-3, 6-4 win over Andrea Petkovic of Germany.
Garcia will play the winner of the quarterfinal between Ana Ivanovic of Serbia and Barbora Strycova of Czech Republic.