The Whites made the worst possible start to the game as England midfielder Mason Mount fired the visitors ahead inside the opening five minutes.
Matters went from bad to worse for Jesse Marsch’s side when Daniel James saw red for a poor challenge on Mateo Kovacic midway through the half.
Chelsea took full advantage of their extra man as Christian Pulisic doubled their tally ten minutes into the second-half and Romelu Lukaku put the seal on a fine away day for Thomas Tuchel’s men when he added a third goal late on.
The result leaves Leeds inside the bottom three and Everton’s goalless draw at already-relegated Watford leaves the Toffees with a two-point advantage over their relegation rivals.
Crucially, Everton and 17th-placed Burnley both hold a game in hand on the Whites as the final fortnight of the season approaches.
Souness told Sky Sports: “I’m thinking Everton are in a good place.
“Everton have a got a bit of momentum right now. We saw the Goodison crowd last week, they were sensational.
“I think Burnley might struggle to win any of those games. Newcastle are a very different team now, they’ve got a bit of grit and determination and fire about them.
“I think Leeds will have to win one of those games as I see it. Leeds have to win a game.
“They’ve got Brighton at home, they’ll see it as a winnable game - but they are down to the bare bones.
“You look at Burnley, Spurs away, Villa away, and then Newcastle at home, I think for Burnley, any of them are super difficult.”
Fellow pundit and former Leeds striker Jermaine Beckford believes his old club are being punished for a lack of discipline.
The red card shown to James means the Whites have been reduced to ten men in their last two fixtures and they currently have the worst disciplinary record in the top flight.
Beckford insisted the Leeds players are trying to prove something to manager Marsch - but are treading a ‘thin line’ with their enthusiastic approach.
“It’s the passion being shown in the wrong way,” the former Everton striker explained.
“Everything that’s happened in the last few games, the Man City game, the Arsenal game, obviously tonight as well, we see Leeds United going behind, and the frustration comes out.
“Players are trying to get in front of opposition players, they are trying to show the manager they’re in here for the long haul, in here to do exactly as you ask, doing everything I can for the team and the fans.
“It’s just a split-second, a blink of an eye, it comes out in the wrong way and it’s something that needs addressing. There is a thin line in showing passion in the right way, and getting it slightly wrong.
“Today, that was definitely wrong.”