Maria Sharapova rued a colossal 52 unforced errors as she slumped to a first-round defeat at the Qatar Open on Monday.
The former world number one and two-time champion in Doha was making her first appearance at the event in five years, but her return ended in disappointment as Monica Niculescu battled back from a set down to win 4-6 6-4 6-3.
Sharapova had looked settled in the opening set and was producing her powerful trademark groundstrokes from the baseline, and when she went 1-0 ahead things looked promising.
However, errors began to creep into her game and Niculescu took full advantage to record an opening-day upset, leaving Sharapova to provide an honest assessment of her performance.
"I thought I did a really good job in the first set and a half, but that's obviously not enough to win the match," Sharapova said.
"I did a good job of winning the longer rallies, even though that's not really what I wanted to get myself into.
"So physically I felt good. I just got pretty passive in the end and started making too many errors.
"I think I have to look at the tape and see why I started going back behind the baseline and not moving forward, not putting the pace on her."
Niculescu could meet top seed Caroline Wozniacki in round three, but will have to get past either Magdalena Rybarikova or Fatma Al Nabhani first.
Five-time semi-finalist Agnieszka Radwanska wasted nine match points before eventually seeing off Mona Barthel 3-6 6-3 7-5.
Seventh seed Caroline Garcia will face Dominika Cibulkova in round two after she battled past Anastasia Pavlyuchenkova – the Slovakian taking the first set tie-break 10-8 before wrapping up the match 6-4 in the second.
Monday also saw straight-set victories for Duan Ying-ying, Mihaela Buzarnescu, Ekaterina Makarova and qualifier Anna Blinkova, while Naomi Osaka battled through back pain to beat Katerina Siniakova 6-4 6-0.
Cici Bellis is also through after Daria Kasatkina was forced to retire at 7-5 4-1 down, the Russian struggling with a neck problem after a fall in the first set.
|It´s a silly question - Carrick insists Pogba has Man Utd future|
|Yates protects Giro lead as Viviani takes fourth stage win|
|Ozil one of Arsenal´s biggest talents - Emery|
|Fastest ODI hundred, 278 not out - De Villiers´ best knocks|
|Deschamps: Rabiot has made a huge mistake|
|Arsenal players can challenge for titles, Emery insists|
|Salah can seal Ballon d´Or with Champions League win - Riise|
|I want Real Madrid to lose Champions League final - Alba|
|Leverkusen sign goalkeeper Hradecky|
|Arsenal job a ´dream come true´ for Emery|
|De Villiers hailed as a ´colossus´ after quitting Proteas|
|Benitez expects Lascelles to stay amid reported Liverpool interest|
|Saha tells Martial: Stay and work for Manchester United future|
|Atletico Madrid defender Savic undergoes hip surgery|
|Bess to make Lord´s debut against Pakistan|
|Vissel Kobe announce news conference amid Iniesta speculation|
|Yan Dhanda leaves Liverpool for Swansea|
|Injured Chung out of French Open|
|I wish he´ll come to PSG - Motta wants Buffon reunion|
|Guardiola praises new Arsenal boss Emery|
|Defensive woes, travel sickness and Ozil´s role - Emery´s Arsenal to-do list|
|WATCH: Anthony Joshua serves up Stephen Curry assist|
|De Villiers announces international retirement|
|Salah not comparable to Ronaldo yet - Karius|
|Toure open to Manchester United switch & wants to play with Pogba|
|Rockets backed up fighting talk, says Harden|
|Europa League master, record return at PSG - Arsenal boss Emery in Opta numbers|
|Curry not taking the blame for defeated Warriors|
|Arsenal confirm Emery appointment|
|Bellamy confirms talks with Brisbane Broncos|
|Ref took Champions League final away from Roma - Under|
|Goals galore and sinking City - Liverpool´s road to the Champions League final|
|Benitez: Winning Champions League changed my life|
|Brewers extend Diamondbacks´ losing streak to six|
|Weidenfeller bids farewell in Schmelzer´s last game as Dortmund captain|
|Owen surprised by Zidane success|
|Rockets break Warriors´ 16-game home postseason win streak|
|Bennett keen to see out contract as Broncos target Bellamy|
|Copa Libertadores Review: Silva helps Cruzeiro into last 16|
|Chargers tight end Henry suffers torn ACL|
|WATCH: Harden dunks all over Green|
|Madrid are linked to 50 players – Ronaldo laughs off Neymar rumours|
|Giants sign wide receiver Shepard|
|Salah wouldn´t improve Real Madrid – Del Bosque|
|Stevens says Tatum should´ve been unanimous All-Rookie First Team selection|
|Rodgers on Bryant: If he ends up here, we´ll welcome him|
|Jets´ Hackenberg dealt to Raiders for 2019 conditional pick|
|Mets sign Bautista, start him same day|
|Warriors´ Iguodala ruled out for game four|
|Guzman called up as Romero replacement for Argentina|
|Gaya signs new five-year Valencia contract|
|Celta appoint Antonio Mohamed as new coach|
|Klopp: Real Madrid have no weaknesses|
|Strauss ´stepping away´ from England role to support wife|
|Argentina rule Romero out of World Cup|
|Emery´s website appears to confirm Arsenal appointment|
|´Inspiring´ Guardiola has made Fleetwood a better golfer|
|Two trophies in a week! Torres leaves Atletico Madrid in style|
|I died a thousand deaths - Yates set for Giro defensive after time trial|
|Hamsik hints at Napoli exit amid China rumours|
|Rowett swaps Derby for Stoke|
|Thiem comfortable in victory as rain delays Wawrinka|
|Schmelzer gives up Borussia Dortmund captaincy|
|Top seed Stephens struggling at Nuremberg Cup|
|This is the wrong information - Vieira rejects Nice speculation|
|France rest Guirado, recall Thomas for New Zealand tour|
|Warriors´ Iguodala upgraded to questionable for game four|
|Simmons, Mitchell unanimous picks for NBA All-Rookie first team|
|AC Milan referred over alleged FFP breaches|
|F1 Raceweek: Ferrari and Red Bull target Monaco upturn|