Victoria Azarenka saved three match points against Japan's Risa Ozaki on her way to winning her comeback match from a year out following the birth of her son at the Mallorca Open.
The former world No 1, who hasn't played tennis on the WTA Tour since the French Open last year, was on the verge of defeat against Ozaki when play was called off for darkness on Tuesday evening.
At 4-5 in the third set, Azarenka broke her opponents serve when Ozaki, the world No 74, had the opportunity to secure victory on Wednesday.
However, Azarenka, who's son Leo was courtside for the match, went on to drop serve again before Ozaki moved 40-0 ahead and within a point of victory at 6-5 in the third.
Azarenka, 27, saved all three of the match points to force a tie-break, which she won on her third match point for a 6-3 4-6 7-6 (9-7) victory despite having trailed 5-3 in the final set tie-break.
"I'm still trying to find my range but mentally, I was there for every point," she said on the official WTA website. "That and the experience helped me through."
Azarenka had made a positive start on her return on Tuesday winning the first set 6-3 before losing the second 6-4 and the initiative in the contest before play was called off for the day.
The Bulgarian will now face Croatia's 7th seed Ana Konjuh in the second round.
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