The Gunners had won just once in their previous five Premier League games but this victory moved them back above Everton and within seven points of fourth-placed Manchester City, with a game in hand.
"For us, the clarity is there, we have to win every game to have a chance of getting in the top four, starting tonight".
Without victory here the top four would have gone.
Of the formation employed in the north east, the Frenchman said: "I just felt that sometimes the team needs to believe in something new, something different, just to find a bit of confidence back". Against Palace and West Brom, we had 70 per cent of the possession and we lost.
"We maybe rode our luck a little bit one or two occasions on crosses, but overall, we were a bit more solid defensively".
"We had practiced on it before at some stage, but we like offensive football so this was a bit more defensive-minded for us. The players care. When you don't win your confidence goes quickly and comes back slowly, so of course you could feel even in the way we played that there was nervousness there". With Arsenal's players walking over to applaud the away supporters after the game (who appeared much happier with them than they did at Selhurst Park last week), Sanchez removed his shirt and made a beeline for a young supporter in the front row, gifting him his shirt as a souvenir.
When asked whether their Champions League hopes would have died had they not won at the Riverside, Wenger replied: "Yes".
"I felt we were focused and committed".
"Despite sometimes hard situations, or some situations that lack clarity, we still can perform".
Arsenal midfielder Alex Oxlade-Chamberlain has claimed that "going back to basics" was what helped his side get back to winning ways against plucky Middlesbrough on Monday night.
"It was significant. We were in a poor situation and we needed to come back with our quality", he told Sky Sports. It was good to come back with the win.
"It's a massive honour to play for a team like Arsenal".
Boro are six points adrift of safety and without a win in 15 Premier League games, but caretaker boss Steve Agnew is refusing to give up hope. "At 1-1 we found a response and managed to win", Wenger added.
"The players were wonderful, I couldn't ask any more of them", he said.
"This group doesn't know how to give in, they will never, ever stop", he said.