LONDON, Great Britain - Russian qualifier Vitalia Diatchenko earned a shocking upset win over No.24 seed Maria Sharapova, 6-7(3), 7-6(3), 6-4 to reach the second round of Wimbledon for the first time in her career.

Despite struggling with injury early in the match, Diatchenko rallied from a set down and though she twice twice trailed Sharapova by a break in the final set, turned the tide to knock out the five time Grand Slam champion in three hours and seven minutes on No.2 Court.

"She swung away," Sharapova said after the match. "She played extremely aggressive. I was playing a little bit too defensively for what I should have been doing. She was there to win it, and she did."

A former World No.71, Diatchenko has been perennially snakebitten by injury throughout her career, famously forced to retire in the first round of the 2015 US Open against Serena Williams as the American began her hunt for the Calendar Year Grand Slam.

Now aged 27, the Russian has finally been healthy enough to play a full schedule, reclimb the WTA rankings, and return to the main draw of a Grand Slam for the first time in almost two years, qualifying with three wins in Roehampton last week.

Sharapova has enjoyed her best results on red clay in the years since winning her maiden major title at the All England Club back in 2004, reaching the semifinals of the Internazionali BNL d'Italia and the quarterfinals of Roland Garros earlier this spring. Still, the former World No.1 appeared in complete control as she took a 5-2 lead in the second set, twice coming within two points of victory.

"I definitely had several chances in the match," Sharapova said. "Although not playing my best tennis, I opened up a few doors and was a couple points away from winning this match. Kept, you know, doing that in the third, as well. But just, you know, sometimes you put yourself in a better or winning position, and you don't finish through. That was the case today."

Diatchenko stood her ground and leveled the match in a second tie-break of the evening, continuing to play catch-up in the decider as Sharapova broke serve in the third and seventh games. 

From the brink of defeat, the qualifier nabbed the final three games of the match, striking a total 31 winners to 32 unforced errors and taking more calculated risks than her countrywoman, who managed 27 winners to 34 unforced errors.

"If I show up and I keep putting myself on the line on days where I'm not performing well, I'm able to change that around. At the French Open I was down 3-0 [in the first round]. I gave myself a chance to go through. I played a great match against Karolina [Pliskova].

"You could work through all those formulas. But at the end of the day, if I wake up and I want to go out and I want to put the work in, I think that speaks for itself. Doesn't need to speak to anyone else. Just needs to speak for me, which is the most important thing."

Standing between Diatchenko and a first-ever Grand Slam third round appearance is young American Sofia Kenin, who defeated Greece's Maria Sakkari in three sets for her first win at Wimbledon.

The 19-year-old American made a major breakthrough last summer at the US Open - playing Sharapova in the third round - and has been in strong form of late, upsetting Caroline Garcia en route to her first WTA semifinal at the Mallorca Open just two weeks ago.