The reigning Greek champions face Ukrainian side Metalist Kharkiv in the second leg of their Europa League round-of-16 tie on Thursday night at the Georgios Karaiskakis Stadium.
Olympiacos took a slender 1-0 lead in the first leg and extended their tally of consecutive clean sheets to 10 in all competitions.
Torosidis knows that achievement was no mean feat as Metalist have been the tournament's most prolific scorers, having netted 23 goals in eight games since the start of the group stage.
The win, Olympiacos' fifth straight victory in Europe, mirrors their domestic form, as Ernesto Valverde's side have reached the semi-finals of the Greek Cup and reclaimed top spot in the Superleague.
The recent success comes after they dropped into the Europa League after exiting the Champions League in the group stage, but Torosidis believes a turnaround in belief has been the key to their success.
"There has been a change in the team's mentality, a fierce determination," Torosidis told UEFA.com. "We really go for it in every match, whether we are up against big names or theoretically smaller teams.
"I hope we can keep this frame of mind, because the results we have been getting add to the prestige of the team.
"In order to keep 10 clean sheets in a row, a team needs - above all - to have luck on their side.
"It is also the product of hard, collective work, not just by the guys at the back. Everyone who has played, up front, in midfield or in defence, has helped to achieve this amazing statistic."
Ukrainian Premier League side Metalist approach the return leg on the back of a 1-1 draw against Metalurh Donetsk in their domestic league.
They are currently third in their league behind Dynamo Kyiv and Shakhtar Donetsk.
"Metalist are skilful and have a lot of pace," Torosidis said.
"Our coach said after the match in Ukraine that the second leg would be harder for us. I absolutely agree with him."