When Serena Williams and Venus Williams stepped onto Wimbledon's Centre Court in 2009, the waiting public were not aware that they were about to see the final grass court encounter between two of the sport's most famous names.
Throughout a decade, the ladies' singles tournament at SW19 had been associated with the name 'Williams', with at least one of the sisters having made the final in nine of the previous 10 years.
It was expected that this showpiece occasion - their fourth facing each other - would be just another to add to a list that had the legs to go on a few more years.
But with Venus's increasing issues with injury and a new breed of talent gracing the WTA Tour, their 2009 match looks almost certain to be the final time that they will share Centre Court in the singles draw.
Ahead of the final, which was being played on Independence Day, Serena had defeated Venus for her previous two Wimbledon titles, but Venus was the defending champion, having beaten her younger sibling in straight sets in 2008.
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Their overall head-to-head record stood at 10-10, which epitomised the competitive nature of the two Americans, and it was no surprise to see them give little away in a first set that was dominated by serve.
However, it was Serena who struck in the tie-break with two stunning forehand winners, before she wrapped up the opening set with a backhand lob.
The two players continued to exchange blows in the second, but Venus suddenly began to falter, maybe under the pressure from her heavily-strapped leg.
Serena broke serve to move a couple of games away from the title, but she had trouble converting championship point, with Venus offering a stubborn resistance on three occasions.
However, after Venus netted, Serena was able to celebrate her first Wimbledon singles title in six years after completing the win in one hour 27 minutes.
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While this looks likely to be the last time that the two sisters face other in a singles encounter at Wimbledon, it wasn't the last time that they shared a court at SW19.
It has almost become tradition to see Serena and Venus team up in the ladies' doubles competition, and before 2009, they had already emerged victorious in 2000, 2002 and 2008 respectively.
That improved to four shortly after Serena's straight-sets triumph in the singles, when they joined forces to beat number three seeds Samantha Stosur and Rennae Stubbs, once again, in straight sets.
They fell at the quarter-final stage in 2010, while they didn't enter in 2011, but the following year, a remarkable fifth title was achieved.
Venus's future participation at Wimbledon is in some doubt, but if we have seen the last of the two most powerful hitters in the game going toe-to-toe on a tennis court, their legacy at SW19 is one that will live long in the memory.