Palma - Former world number one Victoria Azarenka was one game from defeat in her comeback from a year-long absence, against Japan's Risa Ozaki in Mallorca, when play was suspended due to bad light on Tuesday.
The Belarusian, who had not played since the 2016 French Open, started well before Ozaki moved into a 3-6, 6-4, 5-4 lead in the first-round tie.
Azarenka, who took time out of the game to give birth to her first child Leo in December last year, no longer has an official world ranking and entered the grass-court tournament as a wildcard.
The 27-year-old will play at Wimbledon next month though, using her world ranking of sixth from 12 months ago.
The two-time Australian Open champion raced into a 4-0 lead as she won the opening set.
But she showed signs of rustiness as the 74th-ranked Ozaki grew into the contest and forced a decider.
Azarenka displayed her trademark fighting spirit in clawing back to within a single game after falling a double break behind in the third set, but Ozaki will serve for the match when play resumes on Wednesday.
Earlier on Tuesday, French Open quarter-finalist Caroline Garcia saw off former world number one Jelena Jankovic 6-4, 6-4, while 2014 Wimbledon runner-up Eugenie Bouchard let a lead slip to lose to Francesca Schiavone 6-7 (5/7), 6-4, 6-3.
Results from the WTA tournament in Mallorca on Tuesday (x denotes seeding):
Anastasia Pavlyuchenkova (RUS x1) bt Sara Sorribes (ESP) 4-6, 7-5, 6-4
Julia Goerges (GER) bt Lara Arruabarrena (ESP) 6-1, 6-2
Shelby Rogers (USA) bt Beatriz Haddad Maia (BRA) 7-6 (7/4), 6-3
Mona Barthel (GER) bt Anna Kalinskaya (RUS) 7-6 (8/6), 6-4
Francesca Schiavone (ITA) bt Eugenie Bouchard (CAN) 6-7 (5/7), 6-4, 6-3
Roberta Vinci (ITA x6) bt Sara Errani (ITA) 6-2, 6-1
Kirsten Flipkens (BEL) bt Mandy Minella (LUX) 3-6, 6-3, 6-2
Jana Cepelova (SVK) bt Pauline Parmentier (FRA) 6-2, 6-0
Caroline Garcia (FRA x3) bt Jelena Jankovic (SRB) 6-4, 6-4
Sabine Lisicki (GER) bt Kiki Bertens (NED x5) 6-2, 3-6, 0-0 retired
Catherine Bellis (USA) bt Carla Suarez Navarro (ESP x4) 6-3, 7-5
Ana Konjuh (CRO x7) bt Ons Jabeur (TUN) 7-6 (7/1), 4-6, 6-3
Varvara Lepchenko (USA) bt Veronica Cepede (PAR) 3-6, 6-3, 7-6 (7/4)