Zenit's Semak salutes two-goal Shirokov

Sergei Semak said FC Zenit St Petersburg owed a debt of gratitude to Roman Shirokov after the midfielder's two goals secured a pulsating round of 16 first-leg victory against SL Benfica.

Shirokov's first major contribution came on 27 minutes, a composed volley bringing Zenit level shortly after they had fallen behind to Maxi Pereira's close-range finish. Half-time substitute Semak then put the Russian champions ahead in the 71st minute, finding the corner of the net with a clever flick, although it took Shirokov's second of the night two minutes from time to earn Zenit a narrow lead to take to Portugal after Óscar Cardozo had equalised for the visitors.

"Shirokov's goals brought us victory and we owe him a lot of gratitude for his winner," fellow midfielder Semak told UEFA.com. "His first was a good team effort, which he finished really well. He was influential throughout the game. He may have got a bit lucky with his second but he was in the right place at the right time and he deserved that piece of luck."

While the attack-minded Shirokov now has five goals in this season's UEFA Champions League – fewer only than Lionel Messi and Mario Gomez – he will do well to score a better effort than Semak's for 2-1. Aleksandr Kerzhakov's back-heel found Vladimir Bystrov in the Benfica penalty area and the ensuing cross was astutely touched inside the far post by the 35-year-old.

In temperatures of -10C, that was a welcome warmer for the home fans and Zenit's match winner was equally keen to pay tribute to his team-mate. "Semak scored a fantastic goal today," Shirokov, 30, said. "It's becoming a bit of a habit for him to get spectacular strikes. In last year's Europa League he also scored a super goal with his left foot."

Semak, though, played down his contribution, saying: "Luck certainly played its part. I was a bit fortunate with the goal – I looked at the situation I was in and took a shot. Luckily for me it managed to find the bottom corner. I don't think it was down to my skill as a footballer, it was down to luck."

Zenit will therefore take a slender advantage to Portugal on 6 March, when Semak expects an exacting evening. "It will be very difficult in Lisbon because they are a quality side and the return match will be very different from today's encounter. Benfica will be playing at home, so of course we'll be playing in an intimidating atmosphere. The return will be a really interesting game. We just need to prepare well and try to qualify for the next round."