(L - R) Lionel Messi, Xavi and Daniel Alves of Barcelona react during their Champions League semi-final first leg against Chelsea at Stamford Bridge in London April 18, 2012. [Photo/Agencies]

Didier Drogba scored late in the first half and Chelsea mixed luck with resolute defence to keep free-scoring Lionel Messi in check and defeat holders Barcelona 1-0 in their Champions League semi-final first leg on Wednesday.

Barcelona dominated possession, hit the bar and the post and had what looked like a certain goal cleared off the line at a rain-lashed Stamford Bridge.

The Spaniards had 24 attempts on target compared to one by the hosts but Cote d Drogba made the most of his sight of goal when he fired low and hard past Barca goalkeeper Victor Valdes two minutes into stoppage time at the end of the first half.

"We created so many chances, I had no idea we were going to do that, but we failed to score against a very good side who were very strong," Barcelona manager Pep Guardiola told a news conference.

"You have to be a strong side to be in the semi-finals of the Champions League. We knew it was going to be a tough challenge and it was."

Frank Lampard, who like Drogba, John Terry and Ashley Cole, have all been rejuvenated since Roberto Di Matteo took control of the side from the sacked Andre Villas-Boas in early March, began the move after winning the ball from a hesitant Messi close to halfway.

Lampard's raking pass found Brazilian Ramires whose low cross from the left eluded the Barca defenders with Drogba pouncing at the far post to score.

Di Matteo was full of praise for Chelsea's "old guard", who followed up last weekend's 5-1 thrashing of Tottenham Hotspur in the FA Cup semi-finals.

"In the past a lot public opinion said that these boys, the old guard, are over the line and too old to play two games; they have played two games in a short period of time, and I think they gave the answer on the pitch tonight."

However, before and after the goal, Barca were the dominant force with Messi orchestrating most of their attacking moves, but for all his inspired brilliance, he was unable to conjure up a goal either for his teammates or himself. The Argentine forward, who has scored 63 goals for Barca this season, has now failed to score in seven matches against Chelsea.

Didier Drogba (R) of Chelsea and Sergio Busquets of Barcelona jump for a header during their Champions League semi-final first leg soccer match at Stamford Bridge in London April 18, 2012. [Photo/Agencies]

Although this match was about far more than records and statistics, some telling numbers did emerge after a rainswept night in west London.

The defeat was only Barcelona's third loss in 63 games this season and they have now failed to beat Chelsea in the last six matches against them and the Londoners are now unbeaten in 14 matches, home and away against Spanish opposition.

Those figures could all have been very different if Barcelona had scored just once from the many chances they created.

Back in London almost 11 months after beating Manchester United at Wembley last May to lift the European Cup, Barca began as if they had no intention of letting Chelsea into the match at all.

With the tie still evenly balanced ahead of next week's second leg in Barcelona, Guardiola added: "Obviously we are going to try and score and maybe we will have another 24 chances. But it is difficult against a side that defends as deep as Chelsea do."