Spurs host Everton tonight aiming to go level with United and just three points behind leaders City. It is certainly a turnaround in fortunes from when Tottenham eventually got their 2011-12 campaign under way, as they suffered a 3-0 defeat at Old Trafford and were then swept aside 5-1 at home by a rampant Manchester City.
However, since Spurs have been beaten only once, at Stoke, and now lead London's challenge at the top of the table, and Redknapp said: "The belief and the arrival of a couple of players in through the door made a difference to everybody."
He added: "We were one or two players short and we had the [transfer rumour] situation with Luka [Modric]. There was a feeling around the club that it was a difficult period, that first couple of weeks.
"But once we got that out of the way with the international break we were up and running. I knew that once one or two came in that we would push on and we did."
Redknapp challenged his squad to maintain their belief over the second half of the campaign.
"We have improved this year, we are stronger. It is just that belief," he said Redknapp. "We have to believe we can do and I think have that belief that we can keep challenging.
"I am not going to say 'we are going to win the league' as it is going to be very difficult - just look at United's squad and City's squad, they have fantastic players and can make changes everywhere. Their forward players are incredible.
"They know we are going well. Fergie [United boss Sir Alex Ferguson] will look at it and say 'they are going well, they are playing well'. He is not disrespectful to write us off completely.
"It will be difficult for us to finish above them or Man City, but you just never know do you?"
Source: PA
Source: PA