The Gunners manager says a second-leg triumph over the Champions League finalists gave his squad hope they could once again leapfrog their rivals and close a seven-point gap
The Gunners now just need to defeat already-safe Newcastle on Sunday to ensure their qualification to the competition again next season.
After losing 2-1 to Spurs in March, Arsenal were seven points adrift of their north London rivals, but since his side beat Bayern Munich 2-0 in their next game, Wenger knew his side could still challenge the top four.
"The Bayern Munich away game was important and you could feel, after that, we could do it. That helped," Wenger told reporters.
| WE HAVE MOMENTUM - WENGER
|2/1||Tottenham are 2/1 with BetVictor to oust Arsenal and finish fourth
"We then got some new players in and lost the first big games. Suddenly there was scepticism surrounding the team. You could see that."
Despite losing to the German side on aggregate, Wenger claimed he could see improvements in his team that gave him the belief.
He continued: "That was the problem and it took a while to find a formula to have a good balance in the team. Since this has been back we’ve been very efficient.
"Seven points on Spurs is a big comeback and you cannot say Tottenham have not done well recently, they won their games. We needed not to lose any of ours.
"I don’t know how much of a psychological advantage we have over Spurs, what is important is how much effort we put in the game on Sunday. The only advantage we have is our fate depends on our result.
"We don’t look at Tottenham. I’m not concerned by that. It’s just, ‘Let us win the game’. What is at stake is a desire to stay at the top. To play top-level European football.
"There is a difference between the Champions League and Europa League. The Champions League features the best teams. That’s what we want to do. The financial consequences are big but that is not the most important thing for me.
"Of course, we’re on a strong run like the end of last season. We know how to behave to win the game. Recently we’ve shown we can win these games. Let’s just continue to do what we’ve done.
"I had the feeling it could go to the last day. I know that, for a long time, for us when we were seven points behind, we’d be happy for it to go to the last game.
"We’re in a position no one expected us to be in — we have our destiny and fate in our own hands and that’s what you fight for in the game.”