After defeating Bayer Leverkusen in the quarter-finals, Zenit will go into the return leg with the advantage of having scored an away goal, meaning a clean sheet on May 1 would see them through to the final.

It did not look like they would stand much chance when Franck Ribery put the home side ahead in the 18th minute, but they worked their way back into the game and deservedly levelled when Lucio put through his own goal on the hour mark.

As was the case in the quarter-finals, when Getafe left Munich with the same score, the tournament favourites Bayern will now have to win away to reach the final.

Bayern were without their top goalscorer Luca Toni, who was suspended, meaning somebody else had to assume the responsibility for scoring.

That man was Ribery, who put the home side ahead in the 18th minute.

Fernando Ricksen tripped Ze Roberto as he wriggled his way into the penalty area and referee Lubos Michel pointed to the spot without hesitation.

Ribery stepped up to take a rather poor penalty which Vyacheslav Malafeev was able to parry, but Ribery followed in to convert at the second attempt.

The Frenchman had created a chance just seconds earlier with a neat touch to send Ze Roberto through, but the Brazilian could not find either Miroslav Klose or Lukas Podolski in the centre as his low shot was blocked.

It was one-way traffic with the black shirts of Bayern pegging the whites of Zenit back inside their own half.

When they did break free, they showed some of the counter-attacking prowess which had accounted for Leverkusen in the last round.

Konstantin Zyrianov had their first chance of the game in the 20th minute with Oliver Kahn making a good save low to his left after three Zenit players swept forward.

But the better chances in the first half still fell for the home side with Ribery and Ze Roberto both tying the Zenit defence in knots.

Ze Roberto missed the chance to double the home side's lead when he lifted a shot over Malafeev and well wide of the far post.

Bayern were almost made to pay for their profligacy in front of goal when Ivica Krizanac met a dangerous free-kick from Andrei Arshavin at the far post, but failed to get his header on target in the last minute of the first half.

Zenit threatened to get back on terms soon after the break when Arshavin and Zyrianov combined to set up Pavel Pogrebnyak, whose 25 yard shot cleared the crossbar.

Pogrebnyak turned provider for Viktor Fayzulin moments later, shifting the ball to the left where the Zenit midfielder had plenty of time to shoot, but he was unable to find the target from 20 yards out.

The visitors were looking increasingly dangerous going forward and deservedly levelled on the hour mark when Lucio headed a rasping Fayzulin cross into his own goal.

Bayern risked going behind as Zenit's attacking game gained momentum and Pogrebnyak almost created space for a shot on the edge of the area after stealing the ball from Martin Demichelis, who recovered to make a crucial tackle.

The home side lost goalkeeper Oliver Kahn to injury midway through the first half with Michael Rensing replacing him.

The tide slowly began to turn in Bayern's favour, but time was running out when Lucio's powerful shot from 20 yards was tipped over the crossbar by Malafeev with ten minutes to go.

Back at the other end, Ze Roberto had to make a desperate clearance after Fayzulin beat Rensing from close range.

Arshavin and Podolski both missed good chances at the end, meaning there is still all to play for in Russia next Thursday.