A first win at Chelsea since Margaret Thatcher was Prime Minister. A first win away against any of the current top five in the league since early 2016. And, perhaps most significantly of all, a giant step towards finishing as the top team in London for the first time since the 1994/1995 season, and along with it qualifying for the Champions League for the third consecutive year.
There can be no underestimating the importance of Tottenham Hotspur's cathartic 3-1 victory over Chelsea on Sunday evening. This was no April Fools'.
The Lilywhites have had a tough time of it against their second rivals of late. The infamous 'Battle of the Bridge', in which Chelsea snatched a 2-2 draw in a bad-tempered game to end Spurs' title hopes, allegedly left many of the squad in tears after the match, and the 4-2 Chelsea win in the FA Cup semifinal last season would have been equally hard to swallow.
The Blues are also currently the only side to beat Tottenham at their temporary Wembley home in the league this season, after they recorded a 2-1 win there in August. There was no doubt, then, that Spurs were desperate to finally put one over the team that fans despise very nearly as much as Arsenal.
When Alvaro Morata put the Blues ahead after half an hour following some questionable keeping from Hugo Lloris, Spurs supporters may have been forgiven for thinking 'here we go again'. For all the praise that has been heaped upon the club in recent years, question marks have still been raised over their ability to show up in the big games, particularly away against the top sides.
Their record in that aspect is, frankly, lousy: that Man City win was their only one in 19 away games against the so-called Big Six Premier League teams, and their 4-1 collapse at the Etihad in December drew yet more criticism over the frequency in which the side would appear to crumble in the big away games.
Since that bleak day, however, Spurs are unbeaten in the league, and despite their agonizing narrow loss to Juventus in the Champions League, there has not been one match in which you could say they had 'bottled it', or, to use that adjective which rival fans seem to adore, been 'Spursy'.
What made Sunday's win even more impressive was that Spurs were not even at their free-flowing best for much of the game. Chelsea dominated the first half, and it was only through a Christian Eriksen wonder-strike right on the brink of half time that Tottenham went in at the break, probably undeservedly, all square.
They also inflicted the second half damage without a certain Harry Kane, who only came on with around ten minutes to go, showing how far their strength in depth has improved, and shutting up those who still ridiculously claim that Spurs are a 'one man team'.
The scenes in the away end after Dele Alli's two quickfire goals showed how much this victory meant to the fans, but there is something that would bring them even more joy in May. It has become almost a ritual in every Tottenham match now for the commentator to bring up their need to win a trophy, but this victory has surely given Spurs another advantage to add to the 'home' Wembley one going into their huge FA Cup semifinal against Manchester United.
With eight points now separating Spurs from fifth-placed Chelsea, the team should be able to play their league games with a lot less pressure than before, and could only need three or four more wins to effectively seal a Champions League spot. This would lead to fresh minds and fresh legs ahead of the FA Cup game.
The fact that they have beaten a big rival away from home should be a psychological boost for the Lilywhites, and if they can overcome United in the semifinal their opponent for the final could quite possibly be none other than...Chelsea. What a titanic match that would be, and one which could make or break this team who are so agonizingly close to becoming a major force.
For now, though, Spurs can simply enjoy the feeling of finally getting one over the Blues, and hope it won't be another 28 years until they taste that winning feeling at Stamford Bridge again.