The Black Cats have given themselves a genuine chance of Barclays Premier League survival in the most unlikely of circumstances after taking four points from trips to the Etihad Stadium and Stamford Bridge with few onlookers giving them any hope of returning with tangible reward.
They remain three points adrift of safety and at the foot of the table, but both situations could change significantly this weekend if they manage to add a home victory over fellow strugglers Cardiff to their recent exploits.
Johnson claims he has not even looked at the fixtures facing the club's main rivals for the drop, but he knows they will be well aware of what Sunderland have done in their last two outings.
He said: "There are still a good few teams who are still right in it yet
We said that after the [Chelsea] game, we said there will be a few teams above us now thinking 'Oh no' after we did that.
"I put myself in their position and if I were them when I saw that result come in on Saturday night knowing I had to play on Sunday, I would be thinking, 'It's just got even tougher'.
"We have definitely given everyone a scare now and the momentum should be with us
With three home games, we couldn't really ask for a better run-in, three home games against teams in and around us."
Midfielder Liam Bridcutt returns to the Sunderland squad for Sunday's Barclays Premier League relegation showdown.
The 24-year-old has missed the last three games for personal reasons but is available once again, as is full-back Phil Bardsley after serving a two-match ban, with the Black Cats attempting to build upon last weekend's shock 2-1 victory at Chelsea.
However, defender Carlos Cuellar will not be risked as he continues his recovery from a hamstring injury, while midfielder Ki Sung-yueng (knee) also remains on the sidelines along with keeper Keiren Westwood (shoulder) and striker Steven Fletcher (ankle).
Striker Craig Bellamy is set to play a part for Cardiff.
The 34-year-old, who has been sidelined due to a virus, is poised for a role in manager Ole Gunnar Solskjaer's squad as Cardiff look to build on collecting four points in their last two games against Southampton and Stoke.
Winger Craig Noone (abdominal injury) is the solitary confirmed non-starter, with Solskjaer reporting no fresh injury concerns following the Stoke clash six days ago.
Peter Whittingham believes it will be "the biggest achievement" of his seven-year stint with Cardiff if the Bluebirds secure Barclays Premier League survival this season.
Whittingham and company face Premier League bottom club Sunderland at the Stadium of Light on Sunday, with three points their sole objective.
If other results work for them, a win in the north east could see Cardiff climb out of the danger zone prior to their final two fixtures against Newcastle and Chelsea.
"It's huge
It's one of the biggest games since I've been here," said midfielder Whittingham, who joined Cardiff from Aston Villa in 2007.
"Along with the cup finals and the play-off finals, it is right up there with those
If we can escape relegation it will be the biggest achievement since I've been here.
"It's always going to be a big game when you know you have to win
The atmosphere is going to be brilliant, it is going to be awesome.
"It's all well and good taking points here and there, but now it is all about winning at Sunderland
It's something we are going to try our best to do.
"We will keep going until it's mathematically impossible for us to stay up
We have to do that
But it would be horrible to lose at Sunderland, and we are not thinking about it."
Source : PA
Source: PA