A goal deep in injury time by Ghanaian star Andre Ayew gave Marseille a 1-0 win over 2010 champions Inter Milan in their Champions League last 16 first leg and cast further doubt over Claudio Ranieri's future on Wednesday.
There was also a late goal in the night's other tie as substitute Valentin Stocker's 86th minute effort gave unheralded Swiss side Basel a shock 1-0 home win over German giants Bayern Munich.
It continued a worrying slump in Bayern's fortunes which has seen the four-time European champions win just three of their last seven games.
Basel's win saw them become only the fifth team in the competition's history to beat both the German side and Manchester United in the same campaign - four of them went on to win the trophy.
Basel had the better of the opening 20 minutes after Bayern's French star Franck Ribery had given them a wake-up call when he broke the offside trap but his shot was turned round the post by the Swiss side's goalkeeper Yann Sommer.
Basel, though, stormed back after that let-off and twice went agonisingly close to breaking the deadlock in a matter of minutes.
First Aleksandar Dragovic's header looked to be heading for the back of the net only for German number one Manuel Neuer to pull off a miraculous stop which still saw the ball bounce along the line before it was hacked clear.
It was the turn of veteran former Swiss international striker Alexander Frei to be left frustrated a minute later as he turned smartly inside the box but while his shot beat Neuer it cannoned off the bar.
Sommer pulled off a great save midway through the second-half as he tipped over the bar a fierce long range effort by Bayern's experienced German fullback Phillipp Lahm.
However, the deadlock was broken as the match entered its closing stages after Jacques Zoua threaded a superb ball to the unmarked Stocker inside the box and he made no mistake sliding the ball between Neuer's legs.