Heather Watson fought back to beat Jodie Burrage in Abu Dhabi as the pair became the first British women to compete in a tour-level main-draw match since September.
British number two Watson, 28, won 4-6 6-2 7-5 against 21-year-old Burrage.
Watson, ranked 58th in the world, had not played at tour level since losing at the French Open on 29 September.
Burrage was making her tour debut and a sign of her potential was shown by her disappointment at not beating Watson.
With the WTA Tour abandoned in the latter months of 2020 because of the coronavirus pandemic, the event in Abu Dhabi has been newly created for 2021.
Its purpose is to help players return to competitive action in preparation for next month's Australian Open and earn money after several barren months without competition.
Several of the world's leading players have been attracted to the event, including Australian Open champion Sofia Kenin.
The 22-year-old American needed an hour to secure the first set in her opener against China's Yang Zhaoxuan before improving to win 7-6 (7-4) 6-2.
Ukrainian second seed Elina Svitolina, Czech former world number one Karolina Pliskova and two-time Grand Slam champion Garbine Muguruza also earned straight-set opening wins on Thursday.
The Abu Dhabi tournament is only the third WTA event being held since the French Open ended in early October.
With no Britons taking part in the tournaments in Ostrava or Linz, the meeting between Watson and Burrage marked the return of British interest at the highest level.
It was an eerie atmosphere as the pair met in a late evening match played without fans and under floodlights in the Middle East.
That did not diminish the intensity and will to win from the two players, however.
Both showed signs of frustration - Watson as she struggled to find rhythm on the early stages and Burrage as she missed opportunities in the decider - before the former's experience saw her through against the world number 263.
Watson goes on to face Russian 17th seed Ekaterina Alexandrova in the last 32.