Chelsea end an 18-year wait for a victory in Italy by recording a 2-0 victory over AC Milan in the Champions League on Tuesday evening.
The Blues went into the contest at San Siro level on points with their hosts and facing the possibility of dropping to the bottom of Group E with two games remaining if results went against them.
However, after Milan were reduced to 10 men when a foul from Fikayo Tomori led to a penalty, Jorginho converted from the spot before a smart finish from Pierre-Emerick Aubameyang doubled Chelsea's advantage ahead of half time.
While Chelsea were always in full control after the restart, the Premier League giants were dealt a blow when Reece James needed to be withdrawn with a knee injury.
With Red Bull Salzburg being held to a 1-1 draw by Dinamo Zagreb, Chelsea now top Group E, but just three points separate first and fourth place with two matches remaining.
On the back of the 3-0 victory at Stamford Bridge last week, Chelsea were full of confidence ahead of the reverse fixture, and that belief only increased when their former defender Tomori was handed a straight red card just after the quarter-hour mark.
After Mason Mount had got in behind the England international inside the penalty area, Tomori tugged the shirt of his ex-club teammate as he went to shoot, denying a goal-scoring opportunity in the eyes of VAR.
Although the decision felt harsh, Tomori could also have few complaints, and Jorginho took full advantage from 12 yards as he sent goalkeeper Ciprian Tatarusanu the wrong way.
Olivier Giroud - another former Chelsea player in the Milan side - should have put the home side level soon afterwards, only to direct a free header from 10 yards wide of the target.
That ultimately proved costly as Chelsea went further in front in the 34th minute, Mount providing the assist for Aubameyang who made a smart run to fire clinically inside the near post from 10 yards out.
With his side able to take their foot off the gas during the second half, Potter would have experienced the perfect night at San Siro had it not been for an injury to James.
The England international was unable to continue after sustaining an issue with his knee, eventually needing to hobble off just after the hour mark.
While James will naturally have concerns about his participation at the World Cup, Potter will be worried about losing another key player for the ongoing hectic schedule after Wesley Fofana also suffered a knee problem last week.
On a more positive note, Chelsea will book their place in the last 16 if they can defeat Red Bull Salzburg in Austria on October 25.
