Vladimir Petkovic has given Poland's players the benefit of the doubt over their inflammatory celebration at Euro 2016 but Wojciech Szczesny could not resist another opportunity to wind up Switzerland's supporters.

Poland, having defeated Pektovic's team 5-4 on penalties following a 1-1 draw in the round of 16 in Saint-Etienne on Saturday, were pelted with objects after enjoying their moment of triumph directly in front of the beaten team's fans.

Gracious in defeat, Petkovic claimed the Poland players must not have considered the impact of their actions, although pictures of the incident would appear to strongly suggest otherwise.

"As we've always looked on everything in a positive fashion I'm going to do likewise here," he said.

"They slipped [mentally] and didn't realise where our fans were in relation to where they were on the pitch."

Szczesny did not play due to a thigh injury but joined in with the impromptu party when Grzegorz Krychowiak scored from the spot to send Poland through to the quarter-finals.

And the Arsenal goalkeeper, who spent last season on loan at Roma, was spotted appearing to drink from one of the cups that landed on the pitch at Stade Geoffroy-Guichard, before giving a 'thumbs up' gesture that did little to improve the mood among that section of the crowd.

"I have to thank the Swiss fans because I could have a drink," he said.

"That's the end where the penalties were taken, it wouldn't make sense to run all the way to other end to celebrate."

Szczesny's former Gunners colleague Lukasz Fabianski, now at Swansea City, has deputised between the sticks in his team's last three matches of the European Championship and the younger man hailed the contribution of his friend and rival.

"I met Lukasz when I was 14 and he was 19," he said.

"I knew he was going to be a top goalkeeper the day I met him. Since he moved to Swansea he's become a top Premier League goalkeeper. He's had a chance to prove himself and I'm delighted for him. I think today he made the difference for us."

And according to Szczesny, Poland can now play with freedom in the quarter-finals.

"It's a big achievement but we'll aim higher. We'll fancy ourselves. The pressure is completely off us now. Now we can really enjoy ourselves. The Greeks did a few years back, they went all the way to final and won it. You never know," he added, referring to the shock outcome of Euro 2004.

Poland will play Croatia or Portugal in the last eight at Marseille's Stade Velodrome on Thursday.