Rebeka Masarova is celebrating a big win…

The 23-year-old half-Spanish tennis player, a qualifier at this week’s ASB Classic, defeated second-seeded Sloane Stephens 6-3, 7-5 (5) on Wednesday as organizers of the WTA Tour event contended with a backlog of singles matches caused by persistent rain.

Matches had to be played indoors and without spectators to ensure the first round of singles was completed.

On a day which was to be notable for the number of American players in action, Stephens struggled to adjust to the indoor setting and fell to the 130th-ranked Masarova in just under two hours.

The match was a holdover from the previous evening; Masarova led 2-1 on serve when play was suspended late Tuesday night. She immediately broke Stephens for 3-1 and, playing behind a strong serve, took the first set 6-3 in 41 minutes.

Masarova took an early 2-0 lead in the second set, but Stephens broke in the fourth game to level at 2-2 and broke again in the sixth game for a 4-2 lead.

But Masarova broke back in the ninth game and came close to doing so again in the 11th game when she had three break points at 0-40 which Stephens was able to save. Masarova went up 6-2 in the tiebreaker and finally sealed the match on her fourth match point to claim her first win over a top-50 player since 2016.

“I thought I played some good points,” Stephens said. “I thought I played well in some moments.

“Obviously, I wish I could have played better and done some things differently but overall, I’m upset but not devastated. It’s the first tournament of year so I have to be realistic and just know there’s stuff to build on.”