The two capital rivals meet at Emirates Stadium on Saturday lunchtime and will both be looking to respond to dropped Premier League points last weekend.
Arsenal blew a two-goal lead and failed with a last-gasp penalty in their 3-3 draw with Fulham, which extended a run of just two wins in seven matches.
But Szczesny, who is back from a long-term ankle injury, thinks a win over Spurs could have the same impact as last season, when Arsenal picked up a thrilling 5-2 win in late February 2012 and went on to lose just two more league games in the campaign.
He told his club's Official Matchday Programme of the North London derby: "It's a massive game and it doesn't really matter what form you are in when it comes around.
"Both teams have had some disappointing results recently. But it's all about commitment in this one and I'm confident we can go out there and get the job done.
"Hopefully it can have the same effect for us that it did in February, when it really kick-started our season.
"It comes a little bit earlier this year, so after a frustrating couple of weeks we hope a similar thing can happen and over a longer period."