Against Manchester City at the Etihad Stadium last Monday night, Chelsea produced a masterclass of a performance to defeat Manuel Pellegrini's men 1-0 and strike a potentially devastating psychological blow in the title race.
Such a remarkable win was settled by a top-class finish, a goal that came courtesy of Serbian defender Branislav Ivanovic - a player who has become immensely important to the Blues over recent seasons.
After signing for Chelsea from Russian Premier League outfit Lokomotiv Moscow during the winter transfer window of 2008, Ivanovic initially struggled to make any sort of impact under Luiz Felipe Scolari at Stamford Bridge and he did not make a first-team appearance for the club for eight months.
Yesterday, it was reported that French champions Paris Saint-Germain are once again interested in Ivanovic.
Now, while such speculation also suggested that the player was keen to remain at Stamford Bridge and had opened talks over a possible extension to his £120,000-per-week deal, it is nevertheless of paramount importance that Chelsea are able to persuade him to stay and do not allow PSG to get their man.
While he obviously did not enjoy the quickest of starts to his Chelsea career, he has gone on to become arguably one of the club's most-important first-team regulars.
Equally adept at playing at centre-back or indeed at right-back, Ivanovic is an incredibly solid and aerially dominant defensive presence who is also, as that sumptuous strike against Manchester City proved so wonderfully, a menacing attacking threat.
Now, while Chelsea - still backed as they are by the financial might of Roman Abramovich - would perhaps be given the funds necessary to replace Ivanovic if he were to leave the club, I find it extremely difficult to believe that they would easily be able to adequately replace the Serbian's influence and importance.
As one of the Premier League's most underrated talents who is in the very prime of his career at 29, it is not difficult to see why PSG and Laurent Blanc would be keen to entice him to Ligue 1.
However, Chelsea would be very foolish indeed to even contemplate the possibility of giving in to such pressure and should press ahead with attempting to extend his current contract.