CHARLESTON, SC, USA - After two matches and four sets played on Sunday, the unseeded duo of Alla Kudryavtseva and Katarina Srebotnik were crowned champions of the Volvo Car Open after defeating No.3 seeds María José Martínez Sánchez and Andreja Klepac in the final, 6-3, 6-3.

"It's been a's always great coming back here to Charleston, the hospitality here is legendary," Kudryavtseva said on-court after the match.

"We won the title from our second try, and I think it's great. Volvo was my first car, so it holds a special place in my heart."

With Saturday's rain delaying the second semifinal and Martínez Sánchez and Klepac already waiting by virtue of defeating Heather Watson and Mihaela Buzarnescu in the lone completed match yesterday, the Russian and the Slovenian were first out on the Althea Gibson Club Court on Sunday morning. 

From a break down, the eventual champions won the last three games of the first set to first defeated Kateryna Bondarenko and Aleksandra Krunic, 7-5, 6-2 to reach their second final of the season in two tournaments played together.

There was no such adversity for the pair in the championship, as neither lost serve in the match. In turn, they broke Klepac in her first service games of each set, and three times overall, en route to winning the title in one hour, 15 minutes.

Added Srebotnik after the match: "I think we both felt a little bit tired in the final, as the level of play was not the same that we played in the tournament, but it was good enough. We already played a match so we were kind of warmed up...but we're really super happy to win two matches in one day -- two big matches, a semifinal and a final."

Klepac and Martínez Sánchez were also seeking their first title of the season in Charleston, but the duo collected their third runner-up finish of 2018.

Previously, they reached the championship matches at the Premier event in Brisbane and the Premier 5 in Doha.

"We're doing really good together," Klepac said on-court after the match. "It's our third final this year and we'll keep on trying to win one."

Kudryavtseva and Srebotnik needed to win two matches on Sunday to claim the trophy. (Arielle SImmons)

Kudryavtseva and Srebotnik first played together this season in February at the St. Petersburg Ladies' Trophy, where they finished runner-up to Timea Bacsinszky and Vera Zvonareva in a match tiebreak, despite winning the first set.

With the win, Kudryavtseva claims the third Premier-level doubles title of her career, while Srebotnik wins her 14th. The Russian won in Brisbane and Dubai alongside Anastasia Rodionova in 2014, while the Slovenian's last Premier-level title came in Doha in 2015, alongside Abigail Spears.

It is the first tour-level title for Kudryavtseva since returning from a ruptured Achilles tendon, which saw her miss seven months from the end of 2016 through early 2017.

Read more: Kudryavtseva kicks off Aussie return with doubles shift

"This was my third final, and I lost the first very first one, we were heavy favorites and we did not do well, and last time, we were up a set," Kudryavtseva said after the match. "This time, we managed to close it."

The pair won their semifinal match earlier in the day on Sunday. (Arielle Simmons)

For the 37-year-old Srebotnik, the title was notable for another reason. The Slovenian raised her second trophy in Charleston, after winning her first alongside Ai Sugiyama in 2008.

On-court, she added: "I would like to thank Alla for playing great today. Two matches in one day, I'm not used to that...but we pulled through in the end. It's great to be back after 10 years...and I'm really happy to hold the trophy again."

"I've always played well here...I love clay in general, and the gap of 10 years, I think is pretty impressive. I wasn't aware of it actually...I don't think about these things anymore, as I treat it the same as every other one. I'm really happy that at this age, I can be competing at this level and winning tournaments."