Four players put themselves at the head of the pack as the clay court season came to a close, but only one can be crowned May's WTA Player of the Month! 

Have a look at the nominees and cast your vote before Thursday at 11:59 p.m. ET! The winner will be announced Friday, June 15.

May 2018 WTA Player of the Month Finalists

Simona Halep: The World No.1 had a coronation in Paris, rallying to win her first Grand Slam title with a three-set comeback over American Sloane Stephens in the final. 

The Romanian, who lost the first five games and first set of her tournament against another American in Alison Riske in the first round, rounded into form over the course of the fortnight, defeating Taylor Townsend, Andrea Petkovic and Elise Mertens without the loss of a set to reach the quarterfinals.

Read more: Halep: 'Since I was 14...I was dreaming of these moments'

In the last eight, she came from a set down to defeat Angelique Kerber, and with a dominant win over Garbiñe Muguruza to reach the final, retained the World No.1 ranking regardless of what transpired in the final.

Trailing 6-3, 2-0 in the final to the US Open champion, Halep engineered a rally by winning 12 of the last 15 games to hoist her first major trophy in her fourth final appearance. 

'I feel complete, but I want to play more' -- listen to Halep in her own words on the WTA Insider podcast in the latest Champion's Corner. 

Sloane Stephens: Despite a runner-up finish in Paris, the US Open champion had a banner fortnight on the terre battue, having never previously advanced past the fourth round.

After holding off Camila Giorgi in the third round - where the Italian served for the match twice in the final set - the 25-year-old went on a tear, taking out Anett Kontaveit, Daria Kasatkina and good friend Madison Keys without the loss of a set to reach her second major final.

The win over Keys secured a little bit of recent history for the now-World No.4, as she ascended to the position of top-ranked American on the WTA.

Read more: Stephens soars to new American No.1

Stephens, who said she was proud, but not satisfied by just reaching the final, was also complimentary towards the Romanian post-match.

"I think winning here is very special for her and I'm glad she finally got her first slam," she said after the match. 

"It's a beautiful thing, very special. No matter how hard the adversity that you go through, there is always light at the end of the tunnel, and I'm glad she finally got her light."

Petra Kvitova: It was another winning streak across another month for Kvitova, who posted a 13-match streak in May en route to winning two more titles.

The Czech won back-to-back titles on the terre battue on home soil in Prague and a record-setting third title in Madrid, bringing her total to a tour-leading four on the season.

Her French Open campaign ended in the third round at the hands of in-form Estonian Anett Kontaveit in two tiebreaks, but with plenty of match wins behind her already this year, the two-time Wimbledon champion is expected to be a force for the grass season.

Elina Svitolina: Svitolina was the queen of Rome once again, as the Ukrainian successfully defended her title at the Internazionali BNL d'Italia.

Rebounding from a second round loss in Madrid to Carla Suárez Navarro, Svitolina took out Petra Martic, Kasatkina, Kerber and Kontaveit with the loss of just one set to reach the final, where she set up a rematch of last year's championship with Halep.

Though the 2017 final went the distance, Svitolina was on song for the duration of the second edition of the Rome match-up, cruising to a 6-0, 6-4 win and her third title of the season.

Who was your May Player of the Month? Vote now!

The winner will be announced Friday, June 15.

You can also vote for your May 2018 WTA Shot of the Month and Breakthrough of the Month.

How it works:

Finalists are selected by wtatennis.com
Winner is then determined by a fan vote on wtatennis.com 

Previous WTA Players of the Month for 2018
January: Simona Halep
February: Petra Kvitova
March: Naomi Osaka
April: Karolina Pliskova