Redknapp was satisfied with the first 42 minutes at Emirates Stadium on Saturday, saying Tottenham were unsettling Arsenal players and forcing the home side to concede possession. But defensive sloppiness by Spurs led to two goals for Arsenal before half time.
"The goals we gave away turned the whole game upside down," Redknapp said. "I thought they (Arsenal) were edgy, they were giving the ball away, the crowd was moaning at every mistake. I thought we were going to come in at half time in great shape.
"There is no gap between the clubs in my opinion," he added. "I think two mistakes turned the game upside down."
Tottenham paid for its defensive lapses with Robin Van Persie putting Arsenal in front and Cesc Fabregas making it 2-0 just 11 seconds after play restarted — Wilson Palacios gave the ball away and Fabregas burst through three defenders before slotting into the net. Van Persie scored again in the 60th minute.
"It was a horrendous second goal," Redknapp said. "It made such a massive difference to the game really. . They walked off at half time as if they played a fantastic first half, the crowd all singing and going wild. It's like 'What a performance this has been.' We walk off, our heads are on the floor. Goals change games unfortunately. For us, the two goals changed the game today."
Spurs have had a good start to the season and are fighting to keep themselves among the top four teams in the Premier League in order to qualify for a first-ever Champions League next year.
"I say that since the first day of the season," he said. "I won't change my mind today. . I believe we can, but we want to show consistency, intelligence."
Wenger found a way to become upset even when his team was winning 3-0, throwing his jacket down. He was trying to communicate with his players to not let Spurs back into the game with the same defensive mistakes Arsenal made last week in a 2-2 draw with West Ham. Arsenal was winning 2-0 before West Ham came back with two late goals.
"I was frustrated. I couldn't communicate with the players because of the noise of the stadium," Wenger said. "I felt it was important for the team not to concede a goal today because of what has happened recently — any goal could have caused panic."