Arsenal left it late to advance to the FA Cup fifth round with a 2-1 win over Huddersfield Town, while Tottenham were humiliated by Fulham.
But the Gunners’ win was soured by a hamstring injury to star midfielder Samir Nasri, who limped from the field in the 33rd minute after pulling up lame chasing a loose ball.
Arsenal took the lead when Nicklas Bendtner’s attempt ricocheted off Huddersfield captain Peter Clarke in the 22nd minute, but the loss of Nasri and a red card to defender Sebastien Squillaci severely affected their rhythm.
Squillaci was given his marching orders three minutes before first-half injury time for blocking last man Jack Hunt’s run towards the area.
Huddersfield pressed for an equaliser in the second half and deservedly found one through Alan Lee, who met Anthony Pilkington’s corner with a menacing header that left Manuel Almunia no chance.
But the introduction of Fabregas after the hour turned the tide in Arsenal’s favour, with the talismanic captain making no mistake from the spot in the 86th minute after Bendtner was felled in the box by Jamie McCombe.
Elsewhere, Manchester City salvaged a 1-1 draw at Notts County courtesy of Edin Dzeko’s first goal in the sky blue shirt.
Neal Bishop headed County into the lead on the hour, and the League One side came within 10 minutes of a massive upset before Dzeko struck.
The former Wolfsburg striker smashed home a late equaliser from Micah Richards’ cross, ensuring the two sides will meet again in three weeks’ time for the right to reach the last 16.
Wolverhampton went down 1-0 at home to Stoke City after Nenad Milijas’ injury-time penalty was saved by Thomas Sorensen.
Robert Huth proved Stoke’s match winner with an 81st-minute header that settled a disappointing fourth round tie at Molineux.
The central defender outmuscled the Wolves defence at a corner to head home and seal the Potters’ first ever FA Cup win against their Midlands rivals at the seventh attempt.
Victor Obinna was the hero at Upton Park, with the Nigerian netting a hat-trick as West Ham United saw off spirited Nottingham Forest 3-2 and eased pressure on struggling manager Avram Grant.
Obinna put the hosts ahead in the fourth minute, but Dele Adebola and David McGoldrick each struck to have Forest up 2-1 five minutes from first-half injury time.
But on-loan Inter Milan winger Obinna drew the Hammers level in the 42nd minute, then clinched the match from the penalty spot seven minutes after the restart to save West Ham’s blushes.
Finally, Tottenham were smashed 4-0 by Fulham in a thoroughly lopsided clash.
Cottagers skipper Danny Murphy scored twice from the penalty spot in the first 14 minutes – the second after an indiscretion that saw Michael Dawson sent packing with a straight red.
Ten-man Tottenham struggled to gain a foothold in the first half and conceded further goals to Brede Hangeland and Moussa Dembele before the break.