Serena Williams turns 40: Looking back at the GOAT's 4 memorable Slam final wins to celebrate her 4 decades on the planet

The transcendent Serena Williams, widely considered the Greatest Of All Time (or 'GOAT'), turned 40 years old on 26 September. Williams continues to transcend the boundaries of age, and she has built an empire that has no parallel in tennis.

There have been numerous ballads penned in tribute to the 23-time Slam champion, but is it even possible to put in words the extent of her greatness?

Williams turned pro back in 1995 as a 14-year-old, and since then has revolutionized tennis through her ground-breaking feats and athleticism. She has been a true trailblazer in fighting for equality and pushing women's sport to the forefront. Her legacy has been unlike anything we have previously witnessed.

As Serena Williams celebrates her 40th birthday and completes four decades on the planet, let's take a look at four of her most epic Grand Slam final victories.

#4 Roland Garros 2002 final - the one that started the rivalry to beat all rivalries

Venus Williams and Serena William at Roland Garros 2002

The 2002 Roland Garros final was a new page in the sensational Williams sisters' rivalry. Venus Williams was already a four-time Major champion at the time, but the 20-year-old Serena Williams was still looking to add to her Grand Slam cabinet after having triumphed at the 1999 US Open.

The younger of the siblings had faced defeat in all her previous encounters against Venus at the Slam level, and she was determined to change that in 2002. Venus and Serena Williams were seeded second and third respectively at the tournament, and they both marched to the summit clash with authority.

During the championship match, Venus Williams squandered an early break in the first set but eventually built up a 5-3 lead anyway. Serena, however, started playing a lot more aggressively towards the end, and grabbed four straight games to secure the first set.

There was no looking back from there, as she raced to a 3-0 lead in the second set. Venus toiled hard to shorten the gap and took the set to *4-3. However, Serena Williams quashed any possibility of a comeback and claimed a 7-5, 6-3 triumph.

The sisters would go on to build an extraordinary rivalry consisting of 31 matches, with Serena winning 19 of them. But the seeds of her dominance were sown on that Parisian afternoon in 2002, marking the start of an era.

Serena Williams would go on to win the next three Majors on the trot, completing the first of her two 'Serena Slams'.

#3 Australian Open 2005 final - the encapsulation of Serena Williams the fighter

Serena Williams and Lindsay Davenport at the 2005 Australian Open

The 23-year-old Serena Williams was a six-time Grand Slam champion at the 2005 Australian Open, and was taking on World No. 1 and compatriot Lindsay Davenport in the final. Davenport was contesting her first Major final since the 2000 US Open, and was facing Williams for the 14th time.

The top-seeded American had started her season on the back of six titles from the previous year, and was carrying plenty of momentum. Williams, however, had beaten her nine times before, and knew what she needed to do to cause an upset (on paper).

Both women had reached the final after claiming hard-fought victories in the semifinals. Serena Williams famously saved multiple match points against Maria Sharapova in her semifinal, which kick-started a decade of dominance in the rivalry that defined her era.

The championship match in Melbourne, however, started with Lindsay Davenport running away to a 4-0 lead in the first set, which she eventually won 6-2. Her active net-play and heavy ball-striking were greatly troubling Serena Williams, who was staring at defeat while serving at 2-2 in the second set.

Williams faced four break points in that game, looking like she was about to fall off the edge each time. But she dug deep to save them all and hold for 3-2.

A break at 3-4 gave Williams the opening she needed to take the match the distance. She didn't drop serve after that, playing some immaculate tennis to reel off seven straight games.

Williams handed a third-set bagel to the top seed to clinch her seventh Grand Slam title - and her first since Wimbledon 2003. We all knew she was a fighter, but the 2005 Australian Open was the first time we got to see the full effect of that in a Slam final.

#2 US Open 2013 final - a match of dizzying quality

Serena Williams and Victoria Azarenka at the 2013 US Open

Victoria Azarenka was seeking revenge at Flushing Meadows in 2013, after having suffered an excruciating loss to Serena Williams at the same venue 12 months earlier. Azarenka had bagged a second Australian Open title that year while Williams had won her second Roland Garros crown.

Williams and Azarenka were the top two seeds at the 2013 US Open, and they ended up facing each other in the final for the 17th time in their careers. The Belarusian had beaten her rival twice that season, and was hoping to bank upon that confidence in the championship match in New York.

The final started with two successive breaks of serve from the duo. The first set stretched to 5-5 but that was when Azarenka faltered, gifting the break to Williams, who then easily served it out.

The second set was a dramatic contest, where the top seed failed to wrap up the match despite leading 5-3. Victoria Azarenka pulled off a stunning comeback to take the second set 8-6 in the tiebreak. It was a period of play that was marked by some spectacular tennis from both ends, with neither woman willing to concede an inch.

But as the decider went on, the Belarusian started showing signs of fatigue. She couldn't match the intensity of Serena Williams, who grabbed the still hard-fought set in 40 minutes to lift her 17th Grand Slam trophy.

The final scoreline read 7-5, 6(6)-7, 6-1 win in Williams' favor, but that didn't do full justice to the sheer quality of tennis that was on display.

#1 US Open 2012 final - the Serena Williams who would not be denied

Victoria Azarenka and Serena Williams at the 2012 US Open

Both Serena Williams and Victoria Azarenka came into the 2012 US Open final with a Grand Slam title for the season under their belt. Williams had won her 14th Major at Wimbledon a month earlier, while Azarenka had lifted her maiden Grand Slam trophy at the Australian Open.

The women were facing each other for the fourth time that year, and the 11th time overall. Azarenka had beaten Williams only once previously, but her newfound status as a Grand Slam winner and World No. 1 made the US Open final a much-anticipated encounter.

Victoria Azarenka had to overcome grueling three-setters against former US Open winners Samantha Stosur and Maria Sharapova on her way to the final. Serena Williams, on the other hand, had a relatively easy path and didn't drop a set prior to the summit clash.

The first set of the championship match saw a commanding serving performance from Williams, who didn't face a single break point. But her serve grew inconsistent soon after and the Belarusian was able to mirror the 6-2 scoreline and clinch the second set.

The decider was a truly nerve-racking affair. Azarenka was the first to break serve but failed to consolidate the advantage, allowing Williams to break back immediately. At 3-3 the American lost her serve to love, and the World No. 1 held soon after to get the chance to serve for the title at *5-4.

However, a slew of unforced errors from Victoria Azarenka coupled with some inch-perfect consistency from Serena Williams meant the set was soon tied at 5-5. Williams then grew from strength to strength to win the next couple of games and register a 6-2, 2-6, 7-5 victory after close to two-and-a-half hours of play.

This was Williams at her stubborn best, refusing to go away despite her opponent doing everything right. If there was one Slam final that perfectly represented everything that Serena Williams stood for, the 2012 US Open final would be it.