Chelsea were made to fight all the way for their place in the record books after a 1-0 victory at Blackburn which owed everything to their Czech keeper Petr Cech.
Arjen Robben may have scored the goal which saw Jose Mourinho's side stretch the gap at the top to 11 points but it was Cech, who brilliantly saved a Paul Dickov penalty, who emerged as Chelsea's key man.
This was Chelsea's eighth consecutive league win - all with clean sheets - and Cech has now gone 781 minutes without conceding a goal, surpassing Peter Schmeichel's 1997 mark of 694 minutes.
Not since Arsenal drew 2-2 on December 12 have their defence been breached in the Premiership - and not since then have an opposing side caused them so many problems.
Blackburn manager Mark Hughes has bought well in the transfer window and his side, allied to their combative approach, proved doughty competitors.
Rovers are, statistically at least, the dirtiest side in the Premiership with the most fouls, the most red cards (five) and the most yellow (48) of any club in the top flight and Chelsea were taken back by their physical approach.
Aaron Mokoena, playing in a holding role in midfield, ended Robben's match after 11 minutes - the Dutch winger limping off with a bruised foot after a clash with the South African.
Robben had done his work by then but without him and the injured Didier Drogba the visitors looked a touch lightweight, especially in attack.
During the brief time Robben was on the field Chelsea looked in control. Former Rovers winger Damien Duff left Dominic Matteo for dead in the first minute after an exquisite dummy and turn, but Mokoena stood tall for Blackburn and cleared the cross.
There was a flicker of hope for the home side when Dickov picked up possession 25 yards from goal but Claude Makelele's block took the sting out of his strike and Cech was able to gather - and claim that record from Schmeichel.
With less than five minutes gone Chelsea asserted their supremacy. Frank Lampard found Robben on the left flank and the Dutchman left Lucas Neill chasing his shadow before rifling a terrific shot low across Brad Friedel to make it 1-0.
Duff kept up the pressure with a long-range shot which swerved but was still comfortable for Friedel but Blackburn did not fold and Robbie Savage had a decent claim that he was pushed in the area by William Gallas.
Mokoena's fierce rising drive from 30 yards only just cleared the crossbar, before Andy Todd came mighty close to breaching that invincible goal with a powerful downward header from Savage's corner which bounced past an unguarded post.
Savage should have done even better when Dickov chested Morten Pedersen's long-throw towards him but skied his effort.
Blackburn were forcing Chelsea into some uncharacteristic mistakes and from one misplaced pass the Wales midfielder sent the ball whistling past the angle.
Chelsea had been warned, and only Cech's brilliance kept them in front. Savage won a penalty when he ran on to Dickov's backheel and had his ankles clipped by Paulo Ferreira.
Referee Uriah Rennie's decision looked spot on but Cech kept his record going, the Czech using all of his 6ft 5in frame to dive to his left to thwart Dickov, then bravely seizing the loose ball to prevent the combative Scot following up.
John Terry lost his temper with Dickov when the striker went diving in again at Cech's feet and an ugly little fracas developed and Terry was fortunate that someone more card-happy that Rennie was not in charge.
Todd won another header at another Savage corner soon after the second half kicked off but this time he was unable to find any direction.
David Thompson then tried an outlandish volley from 30 yards which soared several yards wide.
By the hour-mark it had become apparent Chelsea had been told to match Blackburn's fire with fire and Terry went into Rennie's notebook for tangling once too often with Dickov.
At the same time, Chelsea had retreated into their shell and when they did poke their head out, it was not to great effect as Joe Cole sliced wide from 20 yards.
Dickov earned his own yellow card for persistent misconduct then Lampard, having one of his quietest matches of the season, saw his direct free-kick deflected wide off one of his own players.
Gudjohnsen flicked a volley narrowly wide as Friedel came out of goal, then Ryan Nelsen, who had an outstanding game at centre-back, was alert to see off the same player when he threatened once more.
Dickov could have made up for his penalty miss when the way to goal opened up for him but he did not strike his shot cleanly and Cech was not properly tested.
Lucas Neill sliced wide as injury time approached and - after another unseemly mass melee after Claude Makelele had knocked over Pedersen - Chelsea held on for victory.
