Yusuf Yazici bagged his second hat-trick in three Europa League outings to hand LOSC a stunning 3-0 win in Milan and send them to the top of Group H, while things went south for still-winless Nice as they were beaten 3-1 away to Slavia Prague.
It was a daunting task that faced LOSc as they travelled across the Alps to face the mighty AC Milan on Thursday night, but Christophe Galtier's men did more than rise to the challenge - they eclipsed it.
Galtier: 'My greatest achievement'
Against a side on a legendary unbeaten run of 24 matches, boasting the threat of the enduringly awesome Zlatan Ibrahimovic, LOSC pressed, harried and outplayed their opponents to run out 3-0 winners and take a one-point lead atop Group H at hotel alf-way point of the group stage.
"I had thought we could win, yes. But 3-0 here in Milan, I hadn't dreamed of it, no," admitted Galtier. "On a personal level, I had big victories with Saint-Etienne in European. But beating Milan, who hadn't lost in twenty-four matches, is undoubtedly my greatest achievement."
Fonte: Yazici 'incredible, 'Huge' performance from Sanches
While Portuguese midfielder Renato Sanches was in stellar form in midfield, running Milan ragged with superb technique and passing, it was Turkey playmaker Yusuf Yazici who provided the cutting edge. First from the spot, after he was bustled over in the area by Milan captain Alessio Romagnoli (22', pen.), and then with a quick-fire double early in the second half (55', 58').
"We are really super-happy. We showed character, personality. We played as a team. It's an important victory. Yazici was incredible. The Europa League is his competition. After his [ACL] injury, he worked hard to come back stronger - to experience moments like these," said LOSC captain Jose Fonte, before heaping praise on the scintillating performance from midfielder Renato Sanches. "It was huge. I believe he can have a very, very great career at the highest level. With Lille or another very big team. But when you have the opportunity to have him in your ranks, you must take advantage of it."
LOSC, who remain unbeaten in all competition this season, now turn their attention to the Ligue 1 Uber Eats trip to face Brest on Sunday afternoon.
Nice go down but not out
Meanwhile things weren't so rosy for Nice, who started life without influential captain Dante - out for several months with a ruptured ACL - with a 3-2 beating away to Slavia Prague.
Although Amine Gouiri cancelled out Slavia's opener with fine strike (33') and young substitute Dan Ndoye sparked hopes of a draw in injury time (90'+3), it wasn't enough to cancel out Slavia's dominance and further two conversions.
"It was a frustrating defeat because there was room for improvement. We lacked depth in the game and we never found the solution. We failed because Slavia wanted it more than us," said Nice coach Patrick Vieira. "We tried to play but they, everything they did, they did it at 300%. We were unable to find our rhythm, so it was difficult to pose them problems. We had to do more and we didn't know how to do it collectively."
The defeat leaves Nice third in a relatively tight Group C, just three points off Slavia and Leverkusen and level with Hapoel Beer-Sheva, as they head into Sunday's high-octane Côte d'Azur derby against Monaco at the Allianz Riviera.