Frank Lampard scored twice to become Chelsea's outright record goalscorer as Rafael Benitez's team fought back to beat Aston Villa 2-1 on Saturday and effectively ensure Champions League football next season.
A hugely entertaining and eventful contest at Villa Park saw Paul Lambert's team take an early lead through Christian Benteke and they looked well set when Chelsea's Ramires was sent off on the stroke of half-time.
Benteke though followed him down the tunnel after the restart, however, and it proved a major turning point as Lampard soon equalised before dramatically surpassing former Chelsea striker Bobby Tambling's long-standing club record in the 88th minute by making it 203 goals for the Blues.
Third-placed Chelsea now have a six-point advantage over Tottenham, who have a game in hand in fifth, but have a superior goal difference over their London rivals of 17 goals.
The only negative for the visitors at Villa Park was the sight of John Terry being carried off on a stretcher,casting a doubt over the centre-half's availability for the Europa League final against Benfica in Amsterdam on Wednesday.
Defeat meant relegation-threatened Villa remained on 40 points and the Birmingham club will now anxiously await Wigan's midweek game with Arsenal.
Victory for Wigan could see the Latics defy the drop at Villa's expense if they beat the Midlands club on the final day of the season.
Villa were celebrating by the 15th minute when a fine Yacouba Sylla through-ball sent Benteke through from the left and, after outfoxing Gary Cahill with ease, the Belgium international squeezed a low shot inside Petr Cech's near post.
Chelsea's irritation boiled over just a minute later when Ramires collected his first caution for a cynical lunge on Benteke.
The 19th minute was marked with the traditional 60 seconds of applause for Villa captain Stiliyan Petrov, who announced his retirement this week as he continues his battle against leukaemia.
Brad Guzan once again demonstrated why he was named Villa's player of the year when he reacted superbly to push Lampard's free-kick onto the right post before blocking Juan Mata's close-range attempt from the follow-up.
However, Benteke appeared somewhat fortunate to escape with just a yellow card when replays showed he'd caught Cesar Azpilicueta in the face with an elbow.
The red card was brandished for the first time in the 45th minute, though, when Ramires picked up his second yellow for a high boot on Gabriel Agbonlahor -- leaving them to face the second half with 10 men.
With the extra man advantage, Villa began the second half brightly and Sylla and Agbonlahor both blazed over Cech's crossbar in quick succession.
Yet Benteke's game was brought to a conclusion in the 59th minute when he picked up his second caution for a raised boot on Terry, who collapsed to the ground clutching his chest.
Within two minutes Chelsea were level, with Lampard the all but inevitable scorer.
Eden Hazard rolled possession sideways to the England international who shifted his weight to fool Nathan Baker before rifling a shot beyond Guzan.
Chelsea thought they'd made it 2-1 in the 72nd minute when Sylla, on the line, denied Cahill's shot by the most slender of margins. But the onrushing Ba's follow-up did appear to cross the white paint despite the best efforts of Ashley Westwood.
Referee Lee Mason waved play on, however, and Chelsea's frustration was compounded seconds later when Terry collapsed to the ground clutching his ankle following a collision with Ron Vlaar.
A dramatic finale ensued and after Cech saved well from Westwood, with just two minutes left on the clock Lampard had the final say when he swept home Hazard's cross from close range.
The afternoon ended in even more emotional circumstances when Petrov emerged from the tunnel to lead the end-of-season lap of honour around the pitch.