José Mourinho's statement that Stamford Bridge is a happy hunting ground for him was proved right as FC Internazionale Milano celebrated a notable success over his former club and a place in the UEFA Champions League quarter-finals for the first time in four years.
Samuel Eto'o's late goal increased the Italian titleholders' first-leg advantage and inflict Chelsea FC's first home defeat in the competition since February 2006, ending their run of 21 unbeaten games. Eto'o had also scored the winner on that occasion, a 2-1 win for FC Barcelona, when Mourinho was in the home dugout.
To cap a miserable night for the English side, Didier Drogba was ordered off three minutes from time after tangling with Thiago Motta, leaving Mourinho's current club as deserved winners having missed a number of decent second-half opportunities.
Inter's coach was afforded a generous reception by the home crowd who chanted his name before the start. Then it was down to business and the uncompromising nature of the contest was quickly apparent with a number of shuddering tackles.
Mourinho was clearly anxious about Chelsea's left-sided threat, with Yuri Zhirkov eager to push forward in the slipstream of the in-form Florent Malouda, and deployed Eto'o in what was virtually a right midfield role. The first opening came from that flank, Maicon advancing but his rising shot was no threat to Chelsea's third-choice goalkeeper Ross Turnbull.
The flow was being interrupted by a succession of free-kicks, Diego Milito only centimetres away from connecting with Wesley Sneijder's curling delivery from one such set piece. Michael Ballack had earlier gone close for Chelsea, capitalising on Milito's loose ball only to drag his shot beyond the upright.
That proved a rare lapse in the Inter defence, Maicon epitomising their commitment when he threw himself in front of Drogba to make a vital block. Inter responded and when John Terry misjudged Maicon's cross, Eto'o was not quite alert enough and failed to keep his header on target. The half ended with Lucio and Co under sustained pressure, and from Drogba's astute pass Nicolas Anelka had a golden chance to break the deadlock. Júlio César half-blocked his shot and Motta was on hand to tidy up.
A flurry of bookings launched the second half, Motta and Walter Samuel both picking up cautions that rule them out of the quarter-final first leg. The first chance after the break fell to Eto'o following Sneijder's glorious crossfield pass, but the Cameroonian international delayed his shot and the danger passed.
Malouda was becoming increasingly influential and a rasping drive required quick reactions from Júlio César, who turned it aside down by his near post. That near miss preceded one at the other end, Sneijder combining skilfully with Goran Pandev yet again the striker failed to pull the trigger in time, allowing Zhirkov to intervene.
Milito passed up two more openings and Motta headed over when well-placed. Would Inter regret those misses? The answer came in the 78th minute when the previously quiet Eto'o showed his class in getting the wrong side of Branislav Ivanović to fasten onto Sneijder's pass before dispatching his shot inside Turnbull's right-hand post and take Inter into the quarter-finals for the first time since 2005/06.