Master meets apprentice once again in a mouth-watering London derby on Sunday when Frank Lampard's Chelsea welcome Tottenham Hotspur and former manager Jose Mourinho to Stamford Bridge.
An attention-grabbing fixture at any time, this showdown promises to be even more encapsulating than usual with both teams in fine form and flying high in the Premier League table.
As if there were not enough sub-plots to this beautifully balanced derby already, Sunday's showdown will be the 1,000th match of Roman Abramovich's reign as Chelsea owner.
It is difficult to think of a more fitting fixture to mark the occasion as two of the men most responsible for the club's success in that time go head to head once again.
No English club has won more major trophies than Chelsea's tally of 16 since Abramovich took over, and Mourinho was manager for half of those. Lampard, meanwhile, was a player for 13 of those 16 successes, scoring more goals than anyone else in the Abramovich era while only John Terry has made more appearances.
Abramovich, Lampard and Mourinho are three men without whom it is impossible to write the history of Chelsea now, but Mourinho - having once famously vowed to never manage Tottenham - is now looking to carve his way into the folklore of a London rival.
Having led Chelsea to their first top-flight title for 50 years, Mourinho's aim now is to end an even longer drought by steering Spurs to the crown for the first time since Bill Nicholson's double winners of 1960-61.
Liverpool's injury troubles and Manchester City's worst start to a season for more than a decade have seemingly opened the door for an outsider to launch a genuine title bid this season, and on current form these two sides are right at the front of the queue.
Indeed, heading into the gameweek Tottenham lead the way in top spot, with Chelsea only two points and two places further back. They both boast the joint-best goal difference in the division too.
For Spurs, their win over Manchester City last weekend was a statement of intent as far as their title credentials go, with the added benefit of sending them top of the table with pretty much a quarter of their season gone.
Indeed, regardless of what happens on Saturday, Spurs are guaranteed to have spent at least seven days at the summit this term, which is already more than they managed in their previous 10 seasons combined.
This is the latest stage of a season that Tottenham have started a gameweek top of the table since January 1985, and if they are still leading the way at the end of a run which sees them play Man City, Chelsea, Arsenal, Crystal Palace, Liverpool, Leicester City and Wolverhampton Wanderers in succession then their hopes of finally being crowned champions of England again must start to be taken seriously by everyone.
There are already plenty of reasons for Spurs supporters to start dreaming, then, and victory at Stamford Bridge would also seal their best-ever start to a Premier League season.
Given their truly terrible record away to Chelsea, such a result would be perhaps more significant than last weekend's victory over Man City, but they have every reason to be confident.
Spurs have won all four away games so far this season and could become only the fifth team in the Premier League era to win five such games on the bounce at the start of a season - a feat they have only achieved once themselves in their entire history, incidentally in their last title-winning campaign.
Mourinho's men are coming up against a team in fine form themselves, though, and looking at recent results alone there is very little to separate the two sides.
Spurs have won each of their last five across all competitions, including Thursday's 4-0 thrashing of Ludogorets in the Europa League, while Chelsea have won their last six, most recently beating Rennes in the Champions League on Tuesday night.
Indeed, Chelsea's last defeat of any kind came in September at the hands of Tottenham themselves, with Mourinho's side winning an EFL Cup clash on penalties.
In the league alone Spurs could win five games in a row for the first time since December 2018 and are on a league-leading nine-game unbeaten run, while Chelsea are hot on their heels with seven unbeaten.
Even in the goals column there is very little to distinguish the two sides - Chelsea's league-best tally of 22 goals scored is just one better than Spurs, while Tottenham's league-low tally of nine conceded is also just one better than the Blues.
It is that latter statistic which has been most responsible for transforming Chelsea from top-four hopefuls to possible title contenders, with Lampard having seemingly fixed the defensive issues which undermined their chances earlier in the campaign.
Nine of those 10 goals Chelsea have conceded came in their opening five games compared to just one in their last four, and if they can keep Tottenham's deadly duo of Harry Kane and Son Heung-min at bay this weekend then it could give them a victory worth much more than simply bragging rights.
Chelsea Premier League form: WDDWWW
Chelsea form (all competitions): WWWWWW
Tottenham Hotspur Premier League form: WDWWWW
Tottenham Hotspur form (all competitions): LWWWWW
ampard has confirmed that Christian Pulisic is now back in contention after a hamstring injury, leaving him with the rare luxury of a clean bill of health.
The winger may not be ready to start just yet, but Lampard does also have Kai Havertz available and he could make his first start since his positive COVID-19 diagnosis.
Indeed, there are difficult decisions to make all around, with the likes of Hakim Ziyech, Timo Werner, Callum Hudson-Odoi and Olivier Giroud also pushing for those forward places having all got themselves on the scoresheet recently.
Tammy Abraham can also count himself amongst that group as he attempts to score in three consecutive Premier League games for the first time since September 2019; he has now scored 18 top-flight goals since the start of last season, which is twice as many as any other Chelsea player.
Amidst all that competition, perhaps the most crucial position of goalkeeper has now been nailed down, with Edouard Mendy keeping seven clean sheets in his 10 appearances for the club - although he did concede on his debut against Spurs.
Mendy will be coming up against arguably the league's two most in-form players as well.
Kane has averaged a goal or assist every 50 minutes so far this season, scoring seven and creating nine more, while Son has found the back of the net nine times himself and could become the first Tottenham player to reach double figures in 10 games since Gary Lineker in 1991-92.
Spurs have had two days fewer to prepare for this game than Chelsea have, and they also have more injury concerns with Toby Alderweireld missing due to a hamstring problem.
Erik Lamela is also absent, but Mourinho is more hopeful over the fitness of Hugo Lloris, Giovani Lo Celso and Steven Bergwijn, all of whom are expected to be in contention.
Matt Doherty is also now back available despite missing out on Thursday, although Mourinho must decide whether the full-back is ready to play from the start after recovering from coronavirus.
Chelsea possible starting lineup:
Mendy; James, Zouma, Silva, Chilwell; Havertz, Kante, Mount; Ziyech, Abraham, Werner
Tottenham Hotspur possible starting lineup:
Lloris; Doherty, Sanchez, Dier, Reguilon; Sissoko, Hojbjerg; Son, Ndombele, Bergwijn; Kane
Head To Head
For all of their good form this season, Tottenham's record at Stamford Bridge remains dreadful - just one win from their last 34 visits in any competition and only one clean sheet from the last 17.
Indeed, home or away Tottenham have only ever won seven of their 56 Premier League meetings with Chelsea, including defeats in each of their last three - more than they had suffered in their previous eight editions of this fixture.
Another victory for Chelsea would make for their best run against Spurs since March 2002, while it would also see Mourinho lose three consecutive league matches against the same manager or club for the first time in his illustrious career.
Indeed, Mourinho has failed to win any of his last five returns to face Chelsea at Stamford Bridge, since picking up a win on his first return with Inter Milan in 2010.
Source: Sports Mole / Barney Corkhill