Chelsea stand one win away from the Premier League title after mounting an impressive comeback to beat Leicester City at the King Power Stadium.
Jose Mourinho's side needed to call on all their reserves of quality and resilience to overcome Leicester City's fiercely determined challenge which earned them a deserved first-half lead through Marc Albrighton.
As expectations of another victory on the road to Premier League safety rose in a thunderous atmosphere, Chelsea responded in the style of champions-elect to earn the victory that means they will be crowned champions for the first time in five years if they beat Crystal Palace at Stamford Bridge on Sunday.
Didier Drogba restored equality early in the second half and further goals from captain John Terry and Ramires wrapped up a win that was testimony to the qualities that have put Chelsea on the brink of glory.
And in a swipe at the Arsenal fans who criticised their approach in Sunday's goalless draw at the Emirates, the visiting fans roared their team to the final whistle with chants of "boring, boring Chelsea".
This defeat ends Leicester's run of four straight wins that has lifted them out of the relegation places but there was enough contained within this display to maintain manager Nigel Pearson's belief that they will retain their Premier League status.
For Chelsea and manager Jose Mourinho, only the formalities remain to be completed as he moved towards his third title at Stamford Bridge, the first of his second spell in charge, after claiming the Capital One Cup earlier this season.
All the factors behind Leicester's recent renaissance were in evidence in a first half when they recovered from serious disruption to take a lead they fully merited.
The Foxes started with real rhythm and tempo but suffered two enforced early changes as Andy King and Robert Huth went off injured to be replaced by Ritchie De Laet and Matty James.
It was still the Foxes, inspired by the ageless Esteban Cambiasso, who held the initiative and it was only fine work from Petr Cech, standing in for Thibaut Courtois as he nurses a slight hip injury, who prevented Leicester from taking the lead.
The veteran blocked superbly from Paul Konchesky as he arrived at the far post, then Albrighton's shot was blocked in the scramble as Chelsea survived.
They did not escape in first-half stoppage time when the pace of Jamie Vardy posed more problems, creating a chance down the left, and when Cesar Azpilicueta lost his footing on a surface made slippy by a downpour, Albrighton beat Cech with a calm side-footed finish.
The King Power Stadium was rocking but Chelsea responded in the manner Mourinho will have demanded with the equaliser three minutes after the restart, the hobbling Drogba sweeping Branislav Ivanovic's cross beyond Kasper Schmeichel.
Drogba should have added a second within moments but scooped a finish high over the bar from Cesc Fabregas's pass.
The great striker had looked every one of his 37 years in the first half but was suddenly a threat and flashed a shot across the face of goal after a powerful run into the area.
As Leicester tired, understandably as their work-rate was so intense, Chelsea took charge and there was an inevitability about the goal that put them in front with 11 minutes remaining. Schmeichel did well to push out Gary Cahill's header from Fabregas's corner but Terry reacted first to push the loose ball over the line.
Chelsea were now in complete command and Ramires provided the final flourish with a superb rising drive from the edge of the area that flew past the helpless Schmeichel.
The title is within reach - it is now a question of when rather than if for Mourinho and Chelsea.