Elise Mertens and Aryna Sabalenka, both accomplished singles players, were the top-ranked doubles team after an out-of-the-world season which saw them clinch the Sunshine Double and their maiden US Open title. Their partnership started with the intention for just the big tournaments, but after their successes, they made it into a permanent one and were rewarded with the status of being the top seeds at the WTA Finals on their debut.

Facing Anna-Lena Groenefeld and Demi Schuurs in their first round-robin match, Mertens and Sabalenka were stunned 5-7, 6-1, [7-10] in the first big upset of the tournament in Shenzhen. The eighth seeds dominated play at the net and broke down the top seeds’ baseline line prowess, stealing the win in three sets despite winning eight fewer points.

Both teams at the net before the match | Photo: Matthew Stockman
Both teams at the net before the match | Photo: Matthew Stockman

Mertens made it to the championships last year with Schuurs, who was ironically her first opponent in Shenzhen this year. The pair ended their successful partnership after the Belgian wanted to focus on singles, but managed to end the year ranked higher than her former partner surprisingly.

Sabalenka had a tough turnaround after lifting the Zhuhai WTA Elite Trophy singles title, taking the court just 32 hours after winning the biggest singles title of her career. Her fatigue was prevalent as she committed quite a number of unforced errors.

Mertens and Sabalenka in action | Photo: Clive Brunskill
Mertens and Sabalenka in action | Photo: Clive Brunskill

21 winners to 13 unforced errors for the top seeds would have almost clinched the win on any other day, especially against a team who hit only 18 winners to a massive 20 unforced errors. Purely looking at the statistical board may be misleading as it was Groenefeld and Schuurs who won all the important points, clinching the best possible start to their Shenzhen campaign.

Groenefeld and Schuurs overcome a mid-match wobble to upset the top seeds

The first five games all went to a deciding point, showcasing how tight the match was going to be. It was expected that Mertens and Sabalenka, who won their last meeting 6-1, 6-2 in Wuhan just a month ago, would sail through this encounter, but Groenefeld and Schuurs certainly altered their tactics which troubled the top seeds.

Three consecutive games from 4-5 down saw the eighth seeds sneak the first set after 46 minutes of play, with Schuurs’ serve from the ad court working extremely well against Sabalenka.

The team of Groenefeld and Schuurs in action | Photo: Clive Brunskill
The team of Groenefeld and Schuurs in action | Photo: Clive Brunskill

Told to be more relaxed and hit with more authority on the court by coach Dmitry Tursunov, Mertens and Sabalenka came out of the blocks firing in the second set and rattled off five consecutive games and dominated the entire set, saving three break points to claim the second set 6-1. They were too good at the baseline, overpowering their opponents and Schuurs and Groenefeld looked lost tactically for a moment.

For the deciding match tiebreak, Schuurs seemed to have re-established her dominance at the net and they quickly opened up a commanding 6-1 lead within a blink of an eye. Mertens and Sabalenka threatened a comeback after minimizing the deficit to just one point, but a costly baseline error from the Belarusian allowed the underdogs to run away with the win in this late-night, high-quality thriller which ended at 1.00 am local time.