After generating enough chances to put the tie beyond doubt, particularly in a first-half they comfortably dominated, Jose Mourinho's side were put under sufficient pressure after the break for Liverpool to head home believing they can turn things around in front of their own supporters.

Chelsea manager Jose Mourinho praised his players especially for their first-half display, though, he regretted them not taking a greater advantage into the half-time break.

However, Mourinho returned to his present pet subject of Chelsea not being awarded penalties and was incensed that referee Markus Merk had not given one in the first-half against Alvaro Arbeloa for handball, though, he was clearly outside the box when the alleged offence took place.

"I don't understand why we don't have penalties," said the Portuguese.

"I just feel and I know for a fact and I don't think anybody can say it wasn't a penalty.

"I don't know why."

Mourinho's counterpart Rafa Benitez said he was happier with the second half performance as he saw his side slide to their first defeat in five Champions League matches between the two sides.

"The game was made up of two different parts," said the ever-cagey Spaniard.

"The first-half we were not controlling it at all but the second a little bit better.

"In the second leg we have to be mindful that Chelsea like to counterattack.

"We just need to score one goal in the second leg and if we can score two like we did in the Premiership against them then we can win.

"Why was I on the touchline in the first-half? Because we were giving the ball away, we needed to be a bit more compact and were doing foolish things in the first-half."

Cole's 29th-minute winner, a close-range effort created by Didier Drogba's power-packed run and astute pass, was a fine goal.

Drogba's well-established capacity for ruffling the composure of the Liverpool defence was underlined as early as the eighth minute, the Ivory Coast striker's knockdown from Ashley Cole's cross teeing up Frank Lampard on the penalty spot.

The England midfielder managed to get his foot over the bouncing ball but his shot was too straight and Jose Reina was able to make a good block.

A minute later, Andriy Shevchenko curled a shot narrowly over the angle of post and bar and Liverpool were reprieved again when Drogba failed to pick out an unmarked Joe Cole in the middle after John Arne Riise's slack back pass had sent him sprinting clear through the inside right channel.

Twenty minutes had elapsed before Liverpool managed to muster a shot on the Chelsea goal, Bolo Zenden's wayward effort only adding to the frustration of the increasingly agitated Rafael Benitez on the touchline.

Dirk Kuyt finally gave Petr Cech something to do shortly afterwards, although a kindly deflection off Ricardo Carvalho ensured his header flew straight to the midriff of the Czech goalkeeper.

Chelsea were soon threatening again and, after Drogba had failed to connect with Joe Cole's inviting cross, Lampard sent a 25-yard free-kick fizzing inches outside the base of Reina's right-hand post.

The pressure finally told in the 29th minute as Chelsea took the lead with a move launched by Carvalho on the edge of his own area.

The Portuguese carried the ball out to the edge of the centre circle before spreading the ball wide to Drogba, who muscled past Daniel Agger and advanced into the area before pulling the ball back behind Jamie Carragher.

Cutting in from the opposite flank at pace, Joe Cole was able to get in front of Alvaro Arbeloa and finish the move with the most straightforward of finishes from eight yards out.

"We'll see the importance next week," said Cole of his effort.

"Disappointed not to go in with more goals at half-time.

"Fatigue set in in the second-half but it was a good battling performance. "We're not going to get over excited with a 1-0 win as its only half-time and we have seen teams with bigger leading margins than us turned over in second legs."

Liverpool's tempo rose predictably in response but it was not until after the break that the visiting side began to pose a genuine threat to the Chelsea goal.

The half-time team talk appeared to have had a particularly invigorating impact on Steven Gerrard, who sent one side-footed shot narrowly over before forcing Cech into a fine save with a left-foot volley from the edge of the area.

In between those efforts, Kuyt had headed an inviting Riise cross over and Carragher was equally wasteful when a Zenden corner found him unmarked at the back post.

Having initially been unsettled by Liverpool's introduction of Peter Crouch, Chelsea gradually rediscovered their composure and began to threaten again in the final quarter of an hour.

But two fine saves from Reina kept out efforts from Drogba and Lampard and ensured Chelsea's win was restricted to the narrowest of margins.