(Reuters) - Borussia Dortmund's Robert Lewandowski scored twice in a clinical 4-2 win at Zenit St Petersburg who were made to pay for some dreadful defending in their Champions League last 16, first-leg tie on Tuesday.
Zenit offered free tea and pies to the visiting fans at the Petrovsky stadium and their players were equally generous as they repeatedly gifted possession to their Bundesliga opponents.
Dortmund grabbed two goals in the first five minutes through Marco Reus and Henrikh Mkhitaryan after Zenit, looking rusty as they started their first match after a two-month winter break, twice lost possession on the halfway line.
Although the hosts fought back with second-half goals from Oleg Shatov and a Hulk penalty, Lewandowski replied on each occasion, helped by some more mishaps in the Zenit rearguard, as he took his tally in this year's competition to six.
The second leg on March 19 should now be a formality for last season's runners-up against opponents who qualified for the last 16 despite mustering only six points in the group stage and were clearly out of their depth in the knockout phase.
"We were incredibly active and aggressive. It's not easy to do that. The team put in a fantastic performance," Dortmund coach Juergen Klopp told reporters.
"This was close to an optimal performance. We pressed to great effect against a dangerous team."
Disappointed Zenit coach Luciano Spalletti added: "...we conceded the two quick goals. It made a big imprint on the match and as a matter of fact decided the game.
"We made too many ridiculous mistakes and were punished. You can't afford these kind of mistakes at this level against opponents like Borussia. If you do you pay a very high price."
Zenit, forced to close several sections of the stadium because of racist incidents in their group game at Austria Vienna, were quickly in trouble when Yuri Lodygin's goal kick was collected by Dortmund on the halfway line.
Marco Reus burst into the area and, although he stumbled, the ball ran kindly to Mkhitaryan and the Armenian fired the ball past Lodygin.
The Zenit goalkeeper had to pick the ball out of his net again 70 seconds later after Zenit incredibly lost possession on the halfway line again following the restart.
This time, Mkhitaryan burst down the right and found Kevin Grosskreutz who laid the ball off for Reus to score with a clinical first-time finish.
Dortmund continued to pen Zenit back in their own half and Reus curled another shot just wide of the post from the edge of the penalty area.
Zenit's Brazil striker Hulk barely got a touch of the ball and their new signing, Venezuela forward Jose Salomon Rondon, bought from fellow Russian side Rubin Kazan, was also isolated.
However, Zenit regrouped after the break and briefly threatened to stage a fightback.
After Lewandowski's powerful effort was turned around the post by Lodygin, the Russians cut the deficit in the 57th minute with a scrambled goal when Shatov fired in from the rebound after Rondon had one effort headed away and then hit the post.
Poland striker Lewandowski, who will join Bayern Munich in June, restored Dortmund's two-goal advantage four minutes later after combining with compatriot Lukasz Piszczek as Zenit were caught out by a counter-attack down the right.
There was renewed hope for the home side when Hulk pulled another goal back with a controversial penalty in the 69th minute, awarded after Viktor Fayzulin dribbled into the area and collided with Piszczek.
But their hopes were crushed again two minutes later when Anatoliy Tymoshchuk dithered and was dispossessed in his own half by Reus, who slipped the ball through for Lewandowski to score with a low, angled shot.
"It was incredibly important to grab two goals so early. They were completely thrown off by that," Dortmund captain Sebastian Kehl told Sky.
"We stayed compact and made it difficult for them to create chances. We were dominant at the end."
Zenit's Belgium midfielder Axel Witsel conceded they face an almost impossible task in the return, saying: "Now we have a difficult task in Dortmund, it is necessary to win 3-0. Only a miracle can help us, but in football everything is possible."
Spalletti added: "...we still have hope. We need to think what we can do on a specific day and in a specific game. We have to show a more consistent performance and avoid the mistakes."
(Writing by Brian Homewood; Additional reporting by Dmitriy Rogovitskiy in Moscow; editing by Ken Ferris)