Two-time Grand Slam winner Garbine Muguruza and 2018 finalist Daria Kasatkina survived tough opening day battles at the Dubai Duty Free Tennis Championships.
Twelfth-seeded Muguruza needed seven match points to overcome Ukraine's Dayana Yastremska 4-6, 6-3, 6-3, while Kasatkina took more than two hours to beat qualifier Magdalena Frech 6-3, 3-6, 6-4.
Canada's Eugenie Bouchard also booked her place in the next round with a straight-sets win over Vera Lapko 6-3, 6-4.
Meanwhile, former champion Sara Errani, tenth seed Anastasija Sevastova and Ekaterina Makarova were some of the big names who crashed out of the first round.

England dismiss Pakistan for 110 to seize control of Lord's test
Raphinha, Fermin score as Barcelona beat Athletic in home opener
Celtic and Rangers to play cup match behind closed doors after pitch invasion
Chelsea and Fulham reach League Cup third round as Welbeck scores on debut
PSG to meet Barca, Man City as Champions League draw throws up marquee ties