Fifth seed Maria Sharapova hit 21 aces en route to a hard-fought 7-5, 7-5 win over 12th seed Belinda Bencic to advance to the quarter final of the 2016 Australian Open, where she will face top seed Serena Williams, whom she has not beaten in their last 18 meetings.

Sharapova Wins Titanic Opening Set

Beginning the match with four consecutive holds of serve, both players settled in nicely to this highly-anticipated round of 16 match-up, with Bencic having an answer to everything Sharapova threw at her and vice versa. Both women had their fair share of chances to get the early break, but were both unable to convert any of their opportunities as the other was always able to serve their way out of trouble.

However, in Sharapova's fifth service game at 2-all, Bencic drew first blood, moving her Russian counterpart from side-to-side before forcing an inevitable error to break for 3-2. Sharapova, however, is one of the best returners in the women's game today, and answered with an immediate break of her own, breaking straight back with an emphatic return winner, one of the many keys to her victory. From there, the pair exchanged another pair of breaks before Sharapova took the initiative to get her nose back in front, leading 5-4. Refusing to back down, the Swiss Miss continued to fight, fending off a set point en route to holding and restoring parity at five-games-apiece. In the game that followed suit, Sharapova raced to a 40-0 lead but made three unforced errors, pushing the game to deuce and giving Bencic half of a look at a break point. However, the five-time Grand Slam champion showed her experience when it mattered most, going for her shots and forcing errors out of the 18-year-old en route to holding for 6-5. As the opening set crossed the one hour mark, Sharapova began to put her foot on the accelerator, converting her third set point as Bencic's backhand drifted just wide, consequently sealing the opening set for the Russian 7-5 in 64 minutes.

Maria Sharapova serves to Belinda Bencic in her fourth round match of the 2016 Australian Open. | Photo courtesy: Cameron Spencer/Getty Images AsiaPac
Maria Sharapova serves to Belinda Bencic in her fourth round match of the 2016 Australian Open. | Photo courtesy: Cameron Spencer/Getty Images AsiaPac

Sharapova Clinches Decisive Break in Final Game, Advances to Quarter Final Showdown with Williams

The second set began right where the first left off as both women were putting up a fierce fight, not willing to give the other an edge. The first game of the second frame took eight minutes alone, with Sharapova saving a break point with some big serving -- a familiar pattern for the rest of the set.

From there, both women dug themselves out of trouble in their respective games, resulting in a streak of holds until the end of the set. Sharapova would always mount pressure in Bencic's service games but the 18-year-old stood firm, saving a series of break points in order to stay in touch with the former world number one. Sharapova, in contrast, would always begin games on the front foot, but would struggle to close them out before some big serving came to her aid at some of the most crucial moments of the second set.

After holding to lead 6-5, the world number five began to make her move with the finish line in sight, setting up her first match point with a big forehand return winner. However, that was saved with relative ease by Bencic as a tight-looking Sharapova netted a routine backhand down the middle of the court. But the Russian, who is often regarded as the most mentally strong player on the WTA, quickly put the disappointment of missing her first match point behind her as she forced an error out of her Swiss counterpart, consequently earning herself another match point. On her second opportunity, Sharapova hit her backhand return down the middle of the court, which was originally called out but upon further review, it was revealed that the ball clipped the back of the baseline, prompting the umpire to award the point - and ultimately the match - to the fifth seed as Bencic did not make contact with the ball once the call had been made. And with that, the 2008 champion continued her quest for a second Australian Open title with a hard-fought 7-5, 7-5 win over a very tricky young opponent.

"This must be the first match I won on a challenge but it felt like a clean ball -- I felt like it was on the line, I was really positive about it but I thought worst-case scenario we’re back to deuce," Sharapova said when asked about the call on match point.

Maria Sharapova celebrates after winning her fourth round match against Belinda Bencic on day seven of the 2016 Australian Open. | Photo courtesy: Cameron Spencer/Getty Images AsiaPac
Maria Sharapova celebrates after winning her fourth round match against Belinda Bencic on day seven of the 2016 Australian Open. | Photo courtesy: Cameron Spencer/Getty Images AsiaPac

Sharapova will now face Serena Williams, a player she hasn't beaten in their last 18 meetings. However, the Russian embraces the challenge of playing the world number one with open arms, and is prepared to fight until the end.

"I look forward to playing the best in the world and that’s what she’s proven in the last year," the Russian said, who has lost to Williams on three occasions in Melbourne, including in the final twelve months ago.

A Look at the Final Match Statistics

Generally speaking, Sharapova was far from her best as far as her ground strokes are concerned. However, she served exceptionally well, blasting 21 aces past Bencic who was struggling to read the placement of Sharapova's serves. In contrast, the 18-year-old couldn't get a serve past the Russian, hitting no aces in the 94 service points she played. Sharapova was also the aggressor for the majority of the match, hitting 58 winners to 46 winners, compared to Bencic who hit 10 winners and 19 unforced errors. However, the world number five will need to be sharper on break points, especially in her next match against Williams, as she converted just 4 of her 16 break point opportunities.