It is believed United are now in prime position to seal a deal, with rival clubs dropping out of the race because, privately, they believe Sir Alex Ferguson has already secured the player.
Zaha has become one of the most sought after players outside the Premier League, his elevation to the higher level inevitable.
The main issue is when, not if, it will happen with Crystal Palace hoping to keep the £12 million-rated 20-year-old until the summer at least.
Spurs last night moved to distance themselves from Zaha, but it is understood numerous Premier League clubs who were following his progress have taken a step back recently because they are sure he is United-bound.
Palace hoped if a deal was agreed this month, United would agree to loan them Zaha for the rest of the season.
Meanwhile, Robin van Persie has deflected praise from the stellar start to his United career by insisting that the Red Devils are flying high in the Premier League because goals are coming from everywhere.
"It's not all about scoring goals, but obviously that does help. It's great that so many players have scored goals over the season so far," he said.
"December is always a difficult month and I feel we have come through this period as we wanted to and hopefully we can now push on for the rest of the season.
"I have settled into the club quite quickly and I am really enjoying playing in this team. I would like to thank the fans for all their support."
A player who is hoping to have a big impact for Alex Ferguson's men in the second half of the season is Chris Smalling.
Smalling is delighted to be back in the rhythm with Manchester United after overcoming his injury troubles.
He finally made his comeback for the Red Devils in November and is pleased with how things have gone so far. "I feel good," Smalling said. "I've been able to play a few games now and it's just a case of keeping that going.
"I just want to stay injury-free now and hopefully go on a good run; there are lots of important matches coming up."