Only Martina Hingis and Justin Henin had done what Madison Keys tried to do on Thursday.
Keys, unperturbed, still did her mighty best to do it.
Hingis and Henin are the only two players to have beaten sisters Venus and Serena Williams in consecutive grand slam matches, with Kim Clijsters also having beaten the pair in the same major tournament - but not in successive rounds.
If a fortnight of gruelling battles against the world's best was not enough for you, throw in back-to-back clashes with the Williams'.
Keys should not have really beaten the elder sister, Venus, in the Australian Open quarter-finals.
She won the first set, but had treatment in the second for an adductor problem.
The 19-year-old responded to the taping/physio work to down the seven-time major winner, and throw a spanner in the works of a Williams family reunion on Rod Laver Arena.
Then came a much bigger target, in little sister Serena in the semi-finals at Melbourne Park.
An 18-time major winner, without a title here since 2010 and hungry to break the 'drought', the top seed has been running through her matches with her usual swagger - even despite carrying a virus.
So what does Keys do? Breaks Williams' serve at the first time of asking.
Obviously, the narrative thereafter went the way of the world number one to the tune of 7-6 (7-5) 6-2, but the small wins were key for the teenager:
- The two aces to stave off set points in the first-set tie-break.
- Averaging a faster first serve than Williams for the contest - 179km/h to 176.
- The eight - that's right, eight - match points saved in the seventh game of the second set, to force Williams to serve for the match. Redundant as they inevitably were, it showcased her never-give-up attitude.
Breakout tournaments can be dangerous for players, as the hype can swell into something unachievable.
Comparing Keys with Hingis and Henin is one such example. Only thing is, it was not a comparison made on judgement - hard and fast, those two players are the only to have conquered the Williams' - a lazy 25 major titles between them - within two days of one another at a grand slam event.
The teenager was on the brink of trying to beat her childhood idols back-to-back at the first major she had ever surpassed the third round of.
It almost certainly won't translate into immediate (read 2015) success - but Keys, along with the likes of Sloane Stephens, can become a generational player for the United States much like the Williams' have been since the 90s.