Lisbon - Benfica put 10-man Liverpool on the spot on Thursday as the Portuguese side came from behind to win their Europa League quarter-final first-leg clash 2-1.
Liverpool had already suffered a blow beforehand when midfielder Alberto Aquilani was ruled out with an ankle injury.
But they put that behind them by taking an early lead at the Estadio da Luz as Daniel Agger neatly backheeled home the opener on just nine minutes.
But instead of building on that early momentum, the five-time European champions then found themselves down to 10 men after they had Ryan Babel sent off for pushing Luisao, who had angered the Dutch winger for a foul on Fernando Torres.
Babel pushed Luisao in the face and appeared to say something to referee Jonas Eriksson, who promptly flashed the red card.
Matters came to a brief halt when a firework, thrown from the stands, landed very close to the fourth official standing by Pepe Reina's goal and the referee brought the issue to the attention of the UEFA match delegate.
Talented Argentine Angel di Maria, linked with several top English clubs, then drove just over for Benfica as the hosts, despite missing the silky skills of Javier Saviola, began to warm to their task with the extra man.
Liverpool, however, could have made it two when Steven Gerrard fed Torres who netted but from an offside position.
Oscar Cardozo then headed straight at Reina before Di Maria crossed for Ramires, who headed high over the bar before Cardozo headed a fraction over in a purple patch for the hosts.
Cardozo's 59th-minute free-kick came back off Reina's right-hand post but Pablo Aimar then crumpled under Emiliano Insua's tackle and the referee pointed to the spot and Cardozo drove home.
Insua had already picked up a booking after a foul on Aimar which will rule him out of the second leg at Anfield next week.
Further frustration was to follow for Liverpool as more fireworks landed pitchside before Benfica were awarded a second penalty on 79 minutes.
Angel di Maria crossed from the left and the ball hit Jamie Carragher, playing his 621st match for the club, on the arm.
Once again, Eriksson pointed to the spot and Cardozo once again coolly slid the ball home.
Liverpool midfielder Lucas Leiva said: "We are really disappointed. We started really well the game, scored an early goal. We created some chances even with 10 men."
He added: "Now we have to keep going and try to go through in Anfield. The away goal always is important, we knew that."
Torres and Gerrard ended their evening ahead of time, replaced by David Ngog and Yossi Benayoun just prior to another firework landing pitchside.