Everton oust holders on penalties
Chelsea - who were bidding to become the first side in 125 years to win the competition three times in a row - appeared on course for victory when Frank Lampard made the breakthrough in the 104th minute after a 90-minute stalemate.
But Leighton Baines equalised dramatically in the final minute of the tie with a superb free-kick to set up the shootout and Everton triumphed 4-3 on penalties after Nicolas Anelka and Ashley Cole failed to score for the holders. The Merseysiders now face a home fifth-round tie with Reading while Chelsea's focus will switch to the UEFA Champions League, realistically their last chance of silverware this season.
"I knew I was going to score, I knew where the ball was going to go - and that's half the battle," former England international Neville told BBC radio. "We've been practising penalties all week. The manager just told us to hit them as hard as possible."
Neville said he hoped the win would revitalise Everton's challenge in the Premier League, where they are just three points above the relegation zone. "This could be the springboard for us," Neville said. "We've set the standard today and we must not drop below that. There is still plenty to play for in the league if we pull our socks up."
Ancelotti without Luiz, Torres
The defeat will do nothing to ease the pressure at Stamford Bridge, where Carlo Ancelotti's side have suffered a recent decline despite the arrival of Fernando Torres and David Luiz. With Torres cup-tied and David Luiz ineligible, having joined the club after the teams' first meeting, Ancelotti was forced to revert to the group of players that had guided Chelsea through the opening half of the season.
Torres' influence was still felt, however, with Ancelotti opting for a 4-3-3 formation in anticipation of the Spaniard's return against FC Copenhagen next week in the Champions League. In Torres' absence, Didier Drogba was partnered by Salomon Kalou - the scorer of Chelsea's equaliser in the first game - but it was the home side's rearguard that faced the greater test during a well-balanced first half.
Chelsea came closest to scoring when Everton centre-back Phil Jagielka inadvertently headed Lampard's free-kick against his own post. But the visitors' ambitions extended beyond simply keeping Chelsea at bay and with Baines finding space down the left, David Moyes's side created plenty of openings of their own.
Howard denies home side
Everton's Tim Howard was the busier of the two goalkeepers though, and the USA international had to be at his best to deny Florent Malouda twice in quick succession midway through the half. Chelsea beat Everton in the 2009 final and the Merseysiders' determined approach suggested the memory of the game still hurts.
Both sides were desperate for a confidence-boosting victory after struggling in recent weeks but it was noticeable that the visitors' tackles carried an extra snap. An already feisty tie acquired an extra edge moments before half-time when Ramires chased a pass into the box and went tumbling over Howard's arms as the goalkeeper slid out to meet the ball.
Chelsea were convinced they should have had a penalty but referee Phil Dowd felt otherwise, opting to book the Brazil midfielder for diving. The introduction of Michael Essien for the disappointing John Obi Mikel after the break gave Chelsea a more attacking look.
And their positive approach almost brought the desired result when Drogba came close with two half-chances. Chelsea would have had the game wrapped up mid-way through the second half but for Howard's superb reactions.
The goalkeeper's save from Lampard's close-range effort was outstanding and he immediately followed it up with a similar effort when Branislav Ivanovic connected with the resulting corner. Lampard finally made the breakthrough in the 104th minute, finishing from 12 yards, but Baines curled in a stunning free kick to set up the shoot-out.