Bendtner, who got both goals as Denmark came from 2-0 down to level the match before conceding a late winner, revealed branding from Irish bookmaker Paddy Power during celebrations of the equaliser.
The move was part of an orchestrated marking campaign, with the bookmaker tonight [Wednesday] issuing a statement congratulating the Arsenal forward.
Ken Robertson from Paddy Power said: "I'm truly delighted for Nicklas, what a stunning performance tonight [Wednesday].
"I've no doubt that the luck of the Irish thanks to our lucky underpants helped him find the back of the net twice!"
However, UEFA are unlikely to react with the same enthusiasm as Bendtner's actions would appear to be a clear violation of their rules on ambush marketing.
UEFA regulations ban any advertising on players' kits during the tournament.