The hierarchy ingrained in our sport is a rigid one. The Haves are markedly outnumbered by the Have-Nots, and no Tyler Perry is necessary to help tell them apart. Even (or perhaps especially) on a Tour as “No. 1 today, Gone tomorrow” as the WTA, there is an ever-growing standard, replete with rules and exceptions, that must be met for consideration among the elite.

The rise of any potential star is rarely linear. Even the most exponential of initial increases can be mitigated by plateaus, let downs, and slumps. Most dangerous on the road to Havedom, though, is the grey area in between, an athletic purgatory where one anxiously awaits reclassification. It is a time of tremendous scrutiny, where the goalpost can shift with maddening frequency.

Yes, you have now achieved this. But what about that?

For much of the last two years, World No. 4 Simona Halep has done much of the shifting on her own terms. Success at International events led to wins at Premiers. A Premier 5 win in February was parlayed into a Premier Mandatory final in May. By June, the Romanian was a Grand Slam runner-up. A balanced player with a tidy game, Halep lacks the height of a Maria Sharapova. She lacks the power of a Serena Williams.

But most importantly for many, she lacked a win over either of those players.

Through her meteoric rise towards the top of women’s tennis, Halep notched wins – many of them decisive – over five of the other seven women competing at this year’s WTA Finals in Singapore. Conquering nearly all of the most recent major champions and former No. 1s of the last six years, the late-blooming Halep seemed to suffer from poor timing. A three-set victory over the ever-erratic Petra Kvitova in Madrid, for example, lacked the noteworthiness it might have warranted had it happened after the Czech star collected her second Wimbledon crown.

Still, if the former No. 2 was going to best a member of the game’s highest caliber, Sharapova had looked to be the sensible pick. A lopsided 0-5 head-to-head belies three consecutive three-set struggles during which the Romanian – much to her chagrin – brought out some of the Roland Garros champion’s best tennis of 2014.

However she planned to check off the fast-growing black hole on her resume, it seemed doubtful that it would happen this week. Struggling with injuries and confidence issues, the Wimbledon semifinalist bottomed out to an inspired Mirjana Lucic-Baroni in Flushing, and had only won three matches since Labor Day. Playing in only her second event with a round robin format, Halep had been talking up the concept of the WTA Finals for months, and conveyed a similar sentiment after Monday’s win over No. 5 seed Eugenie Bouchard.

“If you lose one match you still have chances to go in the semifinal, so it’s different and it’s good.”

Beating Bouchard was, on its own, a meaningful victory for the Romanian, who had turned her ankle early in the Wimbledon semifinal she would go on to lose to the Canadian. Playing solid, opportunistic tennis, Halep was helped along by wild errors from her fellow Rising Star. In the tight moments of the match, however, she showed great poise on the large, dimly lit stage, and consistently raised her level when it mattered most.

Few would have expected Wednesday’s match against top seed Serena Williams to unfold in similar fashion.

It cannot be ignored that Williams turned in a horrific performance. It must also be remembered that even the most mediocre tennis from the eighteen-time Grand Slam champion is often enough against her decidedly mortal peers. Even at her worst, the World No. 1 had chances make the best of the second set, earning six break points – two of them coming in the final game of the match.

Halep continued to flip the script with clutch serving and offensive baselining, yanking the American all over the court and drawing 36 errors in total. Those who chuckled over the Romanian’s admission that her serve was her favorite shot were silenced when the leader of the Red Group punctuated each set with an ace.

In just over an hour, Simona Halep erased the biggest knock against her legitimacy, the very thing that allowed many to dismiss her as a pretender masquerading as something more. She suddenly presided over the fates of her Red Group rivals, all but officially qualifying for the semifinals herself. The Have-Not became a Have all at once, and a powerful one at that.

The goalpost will undoubtedly shift again. Yes, you have now achieved this. But what about that?

But Halep has hardly concerned herself with this or that. Only with onward and upward.