While she improved to beat 197th-ranked Mananchaya Sawangkaew in the first round, she looked undercooked against Potapova.
Russian-born Potapova also made a huge amount of errors in a poor-quality first set which started with five breaks of serve before Raducanu pulled away.
Raducanu served for the first set at 5-4 but was broken back by Potapova, who promptly pulled away in the tie-break.
After Potapova took a lengthy break at the end of the set, she made a fast start to the second and broke twice for a 3-0 lead.
The pair exchanged breaks before Potapova asserted her authority and cruised to victory, with a subdued Raducanu making a hasty exit.
Eyes had inevitably drawn towards the potential meeting with Sabalenka – but this loss was a sharp reminder of where Raducanu’s level remains.
Meanwhile, British qualifier Arthur Fery was also knocked out, beaten 7-6 (7-4) 6-1 6-3 by Argentina’s Tomas Martin Etcheverry in the men’s second round.
