7 biggest upsets at Wimbledon since 2000 ft. Rafael Nadal, Roger Federer and Serena Williams

We are only a few days shy of the commencement of the 135th edition of Wimbledon. Last year, Novak Djokovic won the men's singles tournament by beating Matteo Berrettini in the final, while Ashleigh Barty was the women's singles champion with a three-set win over Karolina Pliskova.

The Australian will not be defending her title as she announced her retirement from the sport a few months ago. Current World No. 1 Iga Swiatek has won 35 matches and six tournaments on the trot and is the heavy favorite to win her maiden Wimbledon title. However, the likes of Ons Jabeur, Paula Badosa and Coco Gauff cannot be written off.

In the men's singles, Djokovic and Rafael Nadal are the favorites. However, Berrettini, Carlos Alcaraz, Felix Auger-Aliassime and Hubert Hurkacz are more than capable of challenging for the title.

We have witnessed numerous upsets at the grasscourt Major over the years. Here's a look at the seven biggest upsets at Wimbledon since 2000:

#7 Virginia Ruano Pascual bt. Martina Hingis, first round 2001

Martina Hingis was the top seed at Wimbledon in 2001 and she was drawn against then World No. 83 Virginia Ruano Pascual in the first round. The Swiss entered the tournament following semi-final runs at the German Open, the Italian Open and the French Open.

However, Hingis was shocked 6-2, 6-4 by the Spaniard. Pascual lost in the second round to Lina Krasnoroutskaya in straight sets.

While Pascual enjoyed a successful career in doubles, beating the World No. 1 in the first round of Wimbledon was among the highlights of her singles career.

#6 Karolina Sprem bt. Venus Williams, second round 2004

Karolina Sprem beat Venus Williams in the second round of the British Major in 2004

After losing in the quarterfinals of the French Open, Venus Williams competed at Wimbledon as the third seed in 2004. She won her first-round match against Switzerland's Marie-Gaiane Mikaelian and then faced Karolina Sprem, who, while unseeded, was the World No. 30.

The Croatian stunned Williams 7-6(5), 7-6(6) to script one of the upsets of the tournament. Sprem later beat Meghan Shaughnessy and Magdalena Maleeva to reach her only Grand Slam quarterfinal, where she was beaten by fifth seed Lindsay Davenport.

Venus Williams was the first top-5 seed to be eliminated from the grasscourt Grand Slam in 2004.

#5 George Bastl bt. Pete Sampras, second round 2005

Pete Sampras was in the twilight of his career in 2002 and entered Wimbledon with a 16-13 record on the season. Ranked 13th at the time, the American was seeded sixth in the competition and beat Great Britain's Martin Lee 6-3, 7-6(1), 6-3 in the first round.

Next up for Sampras was lucky loser George Bastl, who was ranked 145th in the world. The Swiss won the first two sets 6-3, 6-2, but the seven-time Wimbledon champion fought back and took the next two sets to force a decider.

Bastl had the last laugh, however, winning the final set 6-4 to achieve the biggest victory of his career and one of the greatest Wimbledon upsets of all time. For the second successive year, Pete Sampras was eliminated from the grasscourt Major by a player from Switzerland, having lost to Roger Federer in 2001.

It was also the first time since 1991 that the American suffered a second-round defeat at Wimbledon.

#4 Lukas Rosol bt. Rafael Nadal, second round 2012

Rafael Nadal had a pretty disappointing grasscourt season in 2012, where he was eliminated in the quarterfinals of the Halle Open. The Spaniard came into Wimbledon seeded second.

He started strongly by beating Thomaz Bellucci in straight sets and was up against World No. 100 Lukas Rosol in the second round.

Nadal won the opening set in a tie-break, but the Czech gradually gained momentum and won the next two sets 6-4, 6-4 to take a 2-1 lead. The Spaniard won the fourth 6-2 and the match went to five sets. Rosol held strong to take it 6-4 and script one of the upsets of the tournament.

#3 Sabine Lisicki bt. Serena Williams, fourth round 2013

Sabine Lisicki has enjoyed more success on grass than on any other surface. Hence, it's no surprise that her best Grand Slam performances have come at Wimbledon.

The German was seeded 23rd at the grasscourt Major in 2013 and reached the fourth round following wins over Francesca Schiavone, Elena Vesnina and Samantha Stosur.

In the fourth round, Lisicki squared off against defending champion and top seed Serena Williams. She won the opening set 6-2 before the then-World No. 1 took the second 6-1. But Lisicki played some fine tennis in the third set and won it 6-4 to seal her place in the quarterfinals.

The German reached the final at Wimbledon that year, where she was beaten by Marion Bartoli.

#2 Steve Darcis bt. Rafael Nadal, first round 2013

Rafael Nadal was on a 22-match winning streak when he entered Wimbledon in 2013. The Spaniard had won the Barcelona Open, the Madrid Open, the Italian Open and the French Open.

Nadal faced World No. 135 Steve Darcis in the first round and succumbed to one of the most shocking defeats of his career. The Belgian stunned the King of Clay, winning 7-6(4), 7-6(8), 6-4. This was the first time Nadal had been eliminated in the first round of the Grand Slam.

Darcis was forced to withdraw from his second-round match against Lukasz Kubot due to a shoulder injury.

#1 Sergiy Stakhovsky bt. Roger Federer, second round 2013

Sergiy Stakhovsky achieved the biggest victory of his career in 2013

The men's singles final at Wimbledon in 2013 was contested between the top two seeds, but there were several upsets throughout the competition. Perhaps the most notable of these came in the second round.

Roger Federer entered the tournament as the reigning champion and third seed, and started strongly with a 6-3, 6-2, 6-0 win over Victor Hanescu.

In the second round, the Swiss was up against then-World No. 116 Sergiy Stakhovsky. The Ukrainian produced one of the biggest upsets in tennis history by beating Federer 6-7(5), 7-6(5), 7-5, 7-6(5) to reach the third round, where he lost to Jurgen Melzer.

This was Federer's earliest exit at a Grand Slam since losing in the opening round of the French Open in 2003.