Zenit St Petersburg secured a narrow advantage in their UEFA Champions League last-16 tie against Benfica as Roman Shirokov\'s brace helped the hosts to a hard-fought 3-2 win at a frigid Stadion Petrovskiy. With temperatures hovering around the minus-ten degrees centigrade mark, the encounter was a punishing one for both sets of players, but it was the Portuguese visitors who settled first as they took a 21st-minute lead through Maxi Pereira after an error by Zenit goalkeeper Yuri Zhevnov. Zenit, however, were not about to roll over in their first ever appearance in the knockout stage of the Champions League, and pulled level in the 27th minute through Shirokov\'s well-executed volley before taking the lead after the break when Sergei Semak rounded off a brilliant team goal. Benfica looked to have snatched a draw in the 87th minute when another Zhevnov howler allowed Oscar Cardozo to tap in from close range, but just two minutes later Benfica were caught dwelling at the back to allow Shirokov in for his fifth Champions League goal of the season. \"It was a nervous match,\" Zenit manager Luciano Spalletti said. \"My players showed really good skill. They showed a lot of heart to win the match in such a grave situation. However they did exactly what we decided to do ahead of the match. We won deservedly tonight.\" The visitors\' manager Jorge Jesus said he was upset with the result, and was expecting an even tougher battle in the second leg. \"It was really tough to play here,\" he said. \"We allowed Zenit to score three goals, that means we defended poorly this evening. It\'s a pity. But nothing is finished yet. The place in the next round will be decided in the return match. I think it will be even tougher.\"