To mark the end of an incredible 2018 season, we're counting down the Top 5 WTA tournament matches of the year.

Continuing our countdown is the all-teen Moscow River Cup final between Olga Danilovic and Anastasia Potapova, where the 17-year-old Serb became the first player born in the 2000s to win a WTA title.

Top 5 WTA Matches of 2018:
No.5: Kerber d. Safarova, Sydney

No.4: Bertens d. Halep, Cincinnati
No.3: Danilovic d. Potapova, Moscow International

The weeks between Wimbledon and the start of the North American summer hardcourt swing are typically quiet ones as today's biggest names take time to prepare for the final major tournament of the season. Against circuitous odds, the fans who followed to the tour to its inaugural staging of the Moscow River Cup were treated to a thrilling display by the stars of tomorrow, culminating in a championship match between two 17-year-olds.

Read the match report: Danilovic claims first title in Moscow after all-teen tussle

Olga Danilovic and Anastasia Potapova were both playing their first WTA final, a stage neither were likely to reach. The former entered the draw as a lucky loser and the latter, ostensibly a local wildcard. Look more closely and one quickly discerns impressive pedigree from the junior ranks: Danilovic won three Grand Slam girl's doubles titles while Potapova was a Wimbledon champion in 2016.

Each parlayed that early promise into a week of exciting tennis in Moscow, with Danilovic scoring a trio of upsets over Kaia Kanepi, top seed Julia Goerges, and Aliaksandra Sasnovich and Potapova twice rallying from a set down to the home crowd's delight.

Though the WTA tour has long been the place to find teen phenoms, the last all-teen final came at the 2017 Volvo Car Open, when future Top 10 debutante Daria Kasatkina dispatched future French Open champion Jelena Ostapenko on the green clay of Charleston, and Danilovic/Potapova was just the second all-teen final since 2009.

Each born in 2001, the winner would become the first player born in the new millennium to capture a WTA title, setting the stage for a tense clash that lasted well over two hours.

Danilovic rallied from a break down in the opening set to get within one point of victory in the second set. Known for her relentless fight, Potapova turned the tables on her childhood friend to level the match and twice lead by a break in the final set. Five points from defeat, the Serb pulled off one last comeback with the help of a fiercesome lefty forehand to secure a monumental win in Moscow.

Read more: 'I was given this chance, I had to take it' - Danilovic on winning in Moscow

For the effortlessly confident teenager - daughter of basketball star Predrag "Sasha" Danilovic - the title run was a long time coming, though one she couldn't have dreamed possible after falling in the final round of qualifying.

"My mom bought the tickets, by the way, back to Belgrade, because lucky losers in these kind of events, it’s not that easy," she recalled in a phone interview after the match. "I don't think I've ever been a lucky loser in any tournament before.

"So we were in Red Square, just walking around, and my coach [former ATP World No.2 Alex Corretja] called me and he said, ‘Okay, you have to come back, you’re playing tomorrow.’ And I’m like, ‘No, I lost. You were there.’ And he said, ‘No no, you got in, you’re playing tomorrow.’ I’m like, ‘No way!’ We came back very fast to the hotel, to prepare for my match."

Danilovic started the month with an ITF Pro Circuit victory in Versmold, and with easy power in all parts of her game, the teen could think just one thing as she approached the finish line.

"‘Hit the ball. Hit the damn ball!'" she laughed "'Hit the ball and play the point! You’ve got this, it’s here. Play the point, be great.’"

For Potapova, it was another milestone week after starting the year by winning her first WTA main draw match at the St. Petersburg Ladies Trophy, continuing to play her best tennis in her home country.

Read more: Teen titans Danilovic, Potapova shine under US Open spotlight

"It’s actually so special because you’re always playing on the big courts, on the stadiums, with a big crowd who is supporting you always," she said. "It meant a lot to me, and I will make it all to be better, and to make it all for my fans here.

"I’m feeling more confidence, for sure," the Russian added at the US Open. "After that final, I recognized that I can make it anywhere I want, and now I’m enjoying just every second I spend on the court."

By the end of 2018, both young women had made Top 100 debuts. Danilovic peaked at No.96 in October while Potapova finished the year just ahead of her rival at a career-high of No.93. 

The pair met again at the Tashkent Open, and this time it was Potapova who emerged victorious en route to a second WTA final. Danilovic went one step further in doubles, scoring her first title in that discipline alongside Tamara Zidansek.

Looking ahead to 2019, Potapova appears set to make her Australian Open main draw debut, while Danilovic, ranked just outside the cut-off, will likely be a high seed in the qualifying tournament. However the duo follow up their breakthrough seasons, it's clear that the next generation is coming, and the revolution began in Russia.