Steaua Bucuresti hold a surprise half-time lead over European champions Chelsea in the first leg of the sides' Europa League last-16 tie.
The Romanian league leaders broke the deadlock on 34 minutes with a controversial penalty kick.
Ryan Bertrand had his arm on Raul Rusescu's shoulder and was adjudged to have fouled the Steaua forward, who emphatically converted the resultant spot kick.
Rusescu's successful effort was the game's first shot on target.
Branislav Ivanovic had earlier headed over the bar from close range.
Chelsea twice came close to levelling the game late in the opening period, but goalkeeper Ciprian Tatarusanu made two smart saves to deny Yossi Benayoun and then Fernando Torres.
