Just as it seemed Vera Zvonareva had turned a new corner and became the psychologically resilient character which has seen her rise to No. 4 in the world, more than just her defensive backhand was exposed by Kim Clijsters in the Women's Singles US Open Final.
As Clijsters cruised to a 6-2, 6-1 annihilation of her Russian opponent and a third US Open title, the watching world saw the old Zvonareva return again.
Positive self-talk and thought-stopping couldn't even help Vera Zvonareva, as her frustration and anger at not winning deleteriously gripped its corrosive tentacles over her performance, with double faults and unforced errors aplenty in the Russian's game.
Just a day earlier, it was ironically the psychologically resilient Zvonareva who beat a mentally defeated Caroline Wozniacki 6-4, 6-3.
But a day later, it was Kim Clijsters who held it together, proving that weak knees are much less of a burden than weak minds.
Whilst Zvonareva struggled to keep cool mentally, Clijsters had her opponent running left, right, and centre only to then win the point and leave her challenger for the US Open title with nothing but an increased heart rate and an even slimmer chance of winning her own service game.
Such diabolical situations got the better of the all-or-nothing attitude of Zvonareva, who's frustration at her own technical inadequacies made her lose concentration at key points and thus led to several unforced errors and double faults.
With her poor defensive backhand completely exposed, Zvonareva was left clueless as to how she would beat her Belgian counterpart, and simply didn't take enough risks when it mattered most.
And when Russia's current top player did risk it, the predictability of her play meant Clijsters was allowed to dominate on Zvonareva's service games, hence why her serve was broken numerous times.
Even the old towel-on-the-head trick couldn't work for Vera, as she'd return to more mistakes on the court and further frustration; blocking out the situation and starting afresh every few games simply didn't work.
Of course, Kim Clijsters played extremely well and displayed the full repertoire of not only her shots, but also physical capabilities, meaning her opponent had to put in more effort to just stay in the rally, let alone win the point.
But the fact remains that the Belgian really didn't have much pressure to exert on her body and troubled knees, as her opponent on the other side of the net self-destructed in a desperate and failed attempt to improve her self-efficacy.
The epic, close encounter the world was expecting failed to materialise, partly due to a lack of arm and leg strength, as well as technical problems with the backhand, from Zvonareva.
But for the most part, Zvonareva's failure was down to her old enemy, that weak mind of hers, biting back at the Russian just as much as the impending revenge from Clijsters after losing at Wimbledon and in Montreal in their past two meetings.
Therefore, one could perhaps say this eventual result was coming. This match may have been a close call before play started, but in hindsight, a Kim Clijsters annihilation was always on the cards.
After all, weak knees prevail over weak minds every day of the week.