German legend Steffi Graf is widely recognised as one of the best tennis players in history.
She won 22 Grand Slam titles in a 16-year professional career, the second-most behind Serena Williams (23) since the start of the Open Era in 1968, and the third-most in history behind Margaret Court (24).
Steffi Graf was ranked world No. 1 for 377 weeks and won a total of 107 career titles.
However, there is one achievement in her career that stands out. In 1988, a then 19-year-old Steffi Graf won the first-ever Golden Slam.
A term coined by the media, the Golden Slam is when a player wins all four Grand Slams - the Australian Open, French Open, Wimbledon and US Open - in addition to the Olympic gold medal. Only 12 players have managed the feat in their career to date but the German remains the only player in tennis history - male or female - to achieve the feat in a single year.
Graf is also one of the only four who have managed a Golden Slam in singles tennis. Andre Agassi, Serena Williams and Rafael Nadal are the other three.
It is as daunting as it sounds and requires great effort and adaptability from a tennis player to triumph across hard courts, grass courts and clay courts, all within months of each other.
Steffi Graf, though, had those qualities in abundance - she is the only player in history to have won each of the Grand Slams at least four times.
Here’s how Steffi Graf became tennis’ Golden Slam winner in 1988.
1988 Australian Open
Having won her first Grand Slam title, the French Open in 1987, and risen to world No.1 for the first time, Steffi Graf entered the 1988 Australian Open as the top seed.
The German was in form, winning the first four rounds in straight sets and dropping only 13 games.
Steffi Graf then beat defending champion Hana Mandlikova 6-2, 6-2 in the quarter-finals before ousting compatriot Claudia Kohde-Kilsch 6-2, 6-3 in the semis.
With such devastating form coming into the final, Steffi Graf beat third seed Chris Evert 6-1, 7-6 to claim her first Australian Open crown. It would prove to be the last of Evert’s six Australian Open final appearances.
1988 French Open
Defending champion Steffi Graf was seeded first again at the French Open and swiftly went about beating her opponents, dropping only 11 games until the semi-finals.
Up against fourth-seeded Argentine Gabriela Sabatini in the last four, Steffi Graf faced her first real test, but overcame it with ease, winning 6-3, 7-6 to go through to the final.
In one of the most dominating performances in Grand Slam finals, Steffi Graf whipped Belarus’ Natasha Zvereva 6-0, 6-0 to claim her second-consecutive French Open crown. It lasted just 34 minutes and is the only ‘double bagel’ Grand Slam final.
1988 Wimbledon
Switching to the rapid grass courts for the year’s third Grand Slam at Wimbledon, top-seeded Steffi Graf needed no time to adapt. She won all her matches in straight sets and dropped only 17 games in her run to the final.
In the final, Steffi Graf faced her biggest challenge - up against record six-time defending champion, the legendary Martina Navratilova.
The final began well for Graf as she took a 5-3 lead but Navratilova hit back, winning four games in a row to win the first set.
Navratilova also won the first two games of the second set to take a 2-0 lead and looked on course for a seventh-straight Wimbledon title.
However, a determined Steffi Graf hit back in ferocious fashion, bringing out her famous forehands and groundstrokes to win six games in a row to take the second set and force a decider.
With the momentum firmly on her side, Graf then went on to win the third set 6-1 and claimed her first Wimbledon title, ending Navratilova’s stronghold.
Steffi Graf also won her only Grand Slam doubles title at the 1988 Wimbledon, taking the women’s doubles title partnering Gabriela Sabatini.
1988 US Open
All eyes were now firmly fixed on Steffi Graf entering the US Open, the year’s final Grand Slam.
The German did not disappoint, winning all her matches in straight sets and dropping just 13 games up until the semi-final. In the last four, the great Chris Evert pulled out, giving Graf a rest before the big final.
Up against her Grand Slam-winning doubles partner Gabriela Sabatini in the US Open final, Steffi Graf won the first set before the Argentine hit back in the second.
Unfazed, Graf went on to take the third set in quick time, beating Sabatini 6-3, 3-6, 6-1 to win her first US Open and with it, became only the third player - after Maureen Connolly Brinker and Margaret Court - and the first in the Open Era to win the Calendar Slam (all four Grand Slams in the same calendar year).
The crowning glory though was yet to come.
1988 Seoul Olympics
Steffi Graf was again seeded first for the 1988 Seoul Olympics. Entering the competition in the second round, the German won her first two matches in straight sets.
Steffi Graf dropped her first set of the event against the Soviet Union’s Larisa Savchenko, beating her 6-2, 4-6, 6-3 in the quarter-finals.
After dominating USA’s Zina Garrison in the semis, Graf was up against Gabriela Sabatini for the Olympic gold - the second time in three weeks the German was facing the Argentine in a final.
However, there would no hiccups this time as Steffi Graf overcame Sabatini 6-3, 6-3 in the final to win the Olympic gold medal and complete an incredible Golden Slam.
Steffi Graf would also claim a second Olympic medal - a bronze in the women’s doubles with Claudia Kohde-Klisch - after the pair lost the semi-finals to Czech Republic’s Jana Novotna and Helena Sukova.