The high-profile British player suffered a back spasm earlier in the month, then refused treatment for a painful ant bite a few days ago due to worries she could inadvertently ingest a contaminated substance.
Playing her first competitive match since November, Raducanu downed No.26 seed Ekaterina Alexandrova from Russia 7-6 (7-4) 7-6 (7-2) on Tuesday in a match featuring eight service breaks in the first set and 12 in total.
Raducanu mixed nine aces with 15 double faults, but her serve held up when it mattered most in the second-set tiebreak.
Since becoming the first player - man or woman - to win a grand slam title after coming through qualifying at the 2021 US Open, Raducanu has had to deal with crippling levels of expectation in her home country.
Even her decision to refuse treatment for the ant bite was closely scrutinised, with Raducanu saying high-profile doping cases involving Jannik Sinner and Iga Swiatek had made her more wary than ever.
The 22-year-old's round-two opponent will be American Amanda Anisimova, who downed Argentina's Maria Lourdes Carle 6-2 6-3.
Amanda Anisimova will play Emma Raducanu in the second round. (AP PHOTO)
Anisimova, who has been ranked as high as No.21 in the world, took a break from the sport in 2023 to deal with mental health issues.
The 23-year-old has also been the victim of vicious online trolling.
In other early women's action on Tuesday, ninth-seeded Russian Daria Kasatkina made short work of Bulgarian Viktoriya Tomova, winning 6-1 6-3.
Later on day three, No.4 seed Jasmine Paolini from Italy gets her Open campaign under way against China's Wei Sijia.
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