Robert Huth's late header proved enough for Leicester to beat Tottenham at White Hart Lane and draw level on points with Barclays Premier League leaders Arsenal.
The two sides were meeting for the second time in four days after their FA Cup third round tie at White Hart Lane ended in a draw on Sunday.
This game looked to be going the same way until Huth headed home his first of the season with eight minutes from time to give Claudio Ranieri's side the three points.
With Arsenal conceding a last-gasp equaliser at Liverpool, second-placed Leicester, who had not scored a league goal in over six hours, are only kept off top-spot by an inferior goal difference.
Despite recalls for Tottenham's Harry Kane and fit-again Jamie Vardy - one of nine changes for Ranieri's visitors from the weekend's game - neither could get their names on the scoresheet.
Kane saw a second-half effort saved onto the crossbar by Kasper Schmeichel as he and Spurs counterpart Hugo Lloris both made a number of impressive saves.
Much like in their cup meeting it was the hosts who started the quicker of the two sides, with Christian Eriksen's attempts at replicating his opener drawing a simple save from Schmeichel.
He then played in Dele Alli, who came close to celebrating his new White Hart Lane contract with the opener but the England midfielder could only send his rasping shot wide of the post.
Schmeichel was called into action to make a much more meaningful save as Toby Alderweireld headed Erik Lamela's corner into the ground, with the Leicester stopper diving to his right to claw the ball behind.
The Foxes' first decent chance of the night came as Lloris' poor clearance ended at the feet of Vardy, who charged into the box before teeing-up Shinji Okazaki only for the Japan forward to fire wide.
They came even closer as the half-hour approached, this time Lloris was the saviour as he stretched to tip Danny Drinkwater's angled volley around the post.
Neither goalkeeper was in the mood to be beaten as Schmeichel again kept out Eriksen, with the sides going in level at the break.
Kane blocked a firm Vardy shot as Leicester were on top after the interval before the league's joint-top goalscorer clashed with Jan Vertonghen and then came close to nipping in ahead of Lloris.
Tottenham's England man was to come within inches of opening the scoring moments later as Kane latched onto Lamela's pass but saw his effort turned onto the crossbar by Schmeichel, before Alli's follow-up was blocked behind.
Leonardo Ulloa replaced a tiring Vardy and saw a goalbound effort blocked by Vertonghen after Riyad Mahrez's initial shot was kept out inadvertently by Okazaki.
But no-one could get in the way of Huth's powerful header as the former Chelsea and Stoke defender watched Christian Fuchs' corner onto his forehead and guided it beyond Lloris to claim another big win for Ranieri's men as they draw level with Arsenal at the summit.
If these sides had not seen enough of one another, they do it all over again at the King Power Stadium in a week's time to see who will meet Colchester in round four of the FA Cup.
TWEET OF THE MATCH
"Unbelievable header by Huth and Leicester are winning. Bloody hell I might need to purchase some new pants!" - Gary Lineker revels in Leicester's last-gasp win at Tottenham.
Hugo Lloris: 7
Kyle Walker: 6
Toby Alderweireld: 6
Jan Vertonghen: 6
Ben Davies: 6
Eric Dier: 7
Tom Carroll: 6
Chistian Eriksen: 5
Dele Alli: 6
Erik Lamela: 5
Harry Kane: 6
Mousa Dembele: 6 (On for Eriksen 70mins)
Son Heung-min: 5 (On for Carroll 81mins)
Josh Onomah: 5 (On for Dier 89mins)
Kasper Schmeichel: 8
Danny Simpson: 6
Wes Morgan: 7
Robert Huth: 7
Christian Fuchs: 6
N'Golo Kante: 7
Danny Drinkwater: 7
Marc Albrighton: 6
Shinji Okazaki: 7
Riyad Mahrez: 6
Jamie Vardy: 6
Leonardo Ulloa: 6 (On for Vardy 70mins)
Andy King: 5 (On for Okazaki 76mins)
Nathan Dyer 5 (On for Mahrez 89)
Kasper Schmeichel: Both goalkeepers excelled and were the main reason this entertaining fare remained goalless for so long. But Leicester's Great Dane did superbly well to keep out Kane's close-range effort and, despite some dodgy kicking, showed how valuable he is in a team often praised for their free-flowing, flair players.
MOMENT OF THE MATCH
Robert Huth: The big German defender did not panic as Fuchs' corner drifted towards him and he guided his powerful header home as Leicester secured a win to move onto 43 points - more than enough to keep them in the division...
VIEW FROM THE BENCH
Pochettino spent the evening screaming and berating his players in a manner that suggested he knew just how big a game this was. Seven changes from the cup game proved he always had eyes on this one. Likewise Ranieri, who made nine alterations from Sunday and saw his side break their goalscoring duck through a most unlikely source.
MOAN OF THE MATCH
Can there be one? Leicester's fairytale continues but Spurs also played their part here and were unlucky to be on the losing side. After two highly-entertaining meetings their fourth-round replay may just be worth a watch.
WHO'S UP NEXT
Tottenham v Sunderland (Barclays Premier League, January 16)
Aston Villa v Leicester (Barclays Premier League, January 16)