The two women waging a power struggle at the top of the sport might as well be operating on parallel universes during the opening week. Their matches are on different days, their performances on different planets.
Safina came into New York on the wrong end of criticism and ridicule that was occasionally cruel and certainly unfair. Her "crime" has been to ascend to the No. 1 ranking without having won a Grand Slam title, while Williams, an 11-time Slam champion who lifted the Australian and Wimbledon trophies this year, remains stuck at No. 2.
The issue has created animosity between the women, with Safina angered by Williams' sneering comments earlier this year that appeared to make fun of the Russian and alluded that she did not deserve the top spot.
The argument has weight, but it's no fault of Safina. The WTA ranking system does not give enough reward for major championships, and with Safina outstanding and Serena painfully mediocre in smaller events, the American is still well behind in points and unable to bridge the gap even if she wins the U.S. Open.
Safina is rightly proud of her position and defends it steadfastly when questioned.
"Nobody will take this away from me," said Safina. "There are so many players who won a Grand Slam, but where are they now? Nowhere.
"Some of the players you don't even know that they won a Slam. But No. 1 will always stay there. The people will remember you by being No. 1, not by winning a Slam."
Rogowska took her to 6-4 in the third set, while Barrois led 2-0 in the decider before nerves got the better of her. Next up is Petra Kvitova, an opponent who would normally instill no fear in Safina. But in her current form?
Even before such error-strewn displays from Safina, no one in their right mind truly believed she is the most accomplished player in the world. That has been made excruciatingly clear when it counts, with defeats in all three of her appearances in Slam finals.
Most painful of those was the Australian Open final at the start of the year, when Williams thrashed Safina, losing only three games.
It is performances such as those, as well as blasting to the Wimbledon title, that have boosted Williams' legendary reputation. Yet, it is her ineptitude and ambivalence toward minor tournaments that has kept her at No. 2.
Serena has steered away from the topic of Safina so far, but it's not too much of a stretch to suggest she wouldn't have minded the Russian's early difficulties at Flushing Meadows.
"I have my own mental issues, so I try to get them worked out," Serena said. "Everyone has to battle themselves sometimes in order to win.
"You can never underestimate anyone. Some days, some people have great days. I just go and look at every opponent as the best in the world."
Such is the odd balance of power at the top of women's tennis – you had to wonder if even that comment came with a jagged edge.
For now, the hostilities will simmer beneath the surface, only to emerge if Safina and Serena go head to head in the final. For now, the world No. 1 and the best player in women's tennis exist in their own bubbles.