Shakhtar Donetsk have gone clear at the top of Champions League Group E after goals from Alex Teixeira and Fernandinho inflicted a 2-1 defeat on Chelsea at the Donbass Arena.
The Brazilian pair netted in the early stages of each half as Shakhtar impressed with a dominating display against the defending champions.
Teixeira opened the scoring inside three minutes when he struck low across Petr Cech after the ball had dropped kindly to him in the area.
Another of the Ukrainian outfit's Samba stars, reported Blues target Willian, was a standout performer for the hosts.
After wasting his own goalscoring opportunity, the sought-after playmaker twice set up Henrikh Mkhitaryan, but Shakhtar's top scorer was denied on both occasions by an in-form Cech, to whom Chelsea owe their slim margin of defeat.
The visiting keeper made a string of fine saves at the end of the first half to ensure the deficit was just one at the interval.
However, he was helpless to prevent Fernandinho extending Shakhtar's advantage when the midfielder combined with Teixeira before replicating his compatriot's smart finish.
Eden Hazard, a first-half substitute for the injured Frank Lampard, sloppily conceded possession in the build up for that goal but did provide an attacking threat as Chelsea briefly threatened a comeback.
Both he and Ramires brought smart saves out of Donetsk stopper Andriy Pyatov, who had previously been untested throughout the first hour.
Chelsea's response was short-lived, with most of the only notable chances in the remainder of the match falling to the hosts.
Fernandinho, Mkhitaryan and Tomas Hubschman all narrowly missed opportunities to add to the score, but a combination of an inspired Cech and wasteful finishing meant that the Ukrainians were in for a nervous finish when Oscar pulled one back.
Chelsea's own Brazilian converted Branislav Ivanovic's cut back into an empty net, but it was too little, too late for Roberto Di Matteo's side.
The result sees Shakhtar open up a three-point gap on the Blues ahead of the return fixture in a fortnight's time.
