Eugenie Bouchard's poor run of form continued as the Canadian suffered a first-round exit at the hands of Australia's Ashleigh Barty at the Miami Open.
Wildcard Barty's 6-4, 5-7, 6-3 win sets up an all-Australian clash in the second round of the WTA hardcourt event against 14th seed Samantha Stosur, AFP reported.
"It has been a bit of a struggle," said a stone-faced Bouchard, who was unable to account for her loss of form.
Bouchard was a beaten finalist at Wimbledon in 2014 but, apart from a run to the semi-final at Sydney where she was beaten by Britain's Johanna Konta, she has been unable to make an impact this year.
Barty reproduced the gutsy tennis that helped her secure her maiden WTA title at the Malaysian Open in Kuala Lumpur last month.
Serbia's Jelena Jankovic was another high-profile early exit, the 2008 Miami finalist falling 4-6, 6-4, 7-6 (7/3) to Kazakhstan's Yaroslava Shvedova.
Local favorite and Rio Olympic gold medalist Monica Puig was comfortably dealt with 6-2, 6-4 by Romanian Sorana Cirstea.
The Puerto Rican Miami-resident struggled from the outset and although she battled back well in the second set, Cirstea kept her cool to book a second round meeting with Latvian 19th seed Anastasija Sevastova.
Britain's Heather Watson, who reached the fourth round in Miami last year, was beaten 7-6 (7/4), 6-1 by Romanian qualifier Patricia Maria Tig.
Escobdeo upsets Britain's Evans in Miami
Young American Ernesto Escobedo pulled off a surprise victory in three sets over Britain's Dan Evans in the first round of the Miami Open on Wednesday.
The 20-year-old Mexican-American, who grew up playing on rough public courts in Los Angeles, is playing in his first ATP Masters 1000 series event, having qualified with a straight-sets win over Argentine Renzo Olivo on Tuesday.
For Evans, it was another setback after he went out in the second round at Indian Wells.
Escobedo, ranked 108th, beat the 43rd ranked Evans 7-5, 0-6, 6-3 at CrandonPark thanks mainly to his strong first serve, which included 10 aces.
"This day is very special for me. I qualified for my first Masters 1000 here in Miami and I played a tricky opponent who serves pretty well. It is pretty big to get my first win here," Escobedo said.
"I started pretty slow but once I broke back I felt pretty comfortable and kept patient. In the second set, I just didn't focus at all and my energy was very low but I am just happy to have stepped it up in the third set."
Escobedo will now face 25th-seed Fernando Verdasco in the second round and he can expect plenty of support from a strongly Hispanic South Florida crowd.
There was more US success against British opposition when qualifier Jared Donaldson outlasted 45th-ranked Kyle Edmund 2-6, 7-6 (7/4), 6-2.
Edmund served for the match at 5-3 in the second set and then had three match points in the following game.
Japan's Yoshihito Nishioka triumped in a two-hour battle with Australia's Jordan Thompson.
Nishioka, who reached the fourth round at Indian Wells last week, saved 11 of 14 break points to secure the 1-6, 6-4, 6-3 victory.
France's Benoit Paire beat Slovak Martin Klizan 7-6 (7/4), 6-3 to earn a second-round challenge with 21st seed Pablo Cuevas.
There was an unusual stoppage during German veteran Tommy Haas's narrow 6-7 (5/7), 6-3, 7-5 loss to Czech Jiri Vesely when the game was halted due to an iguana on top of the scoreboard. The creature was eventually taken away by officials, but not before it scampered across the court.
Image: Canada's Eugenie Bouchard wears a dejected look during her match against Australia's Ashleigh Barty at the Miami Open in Crandon Park Tennis Center in Key Biscayne, Florida, on Wednesday
Photograph: Julian Finney/Getty Images