Not many Tottenham fans would have foreseen Mauricio Pochettino becoming Chelsea boss following the famous Battle of the Bridge.
Eight years on from the 2016 clash, though, the Argentine is still using a key lesson he learnt playing against his current club on what proved to be a heartbreaking night for Spurs.
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Tottenham, managed by Pochettino, headed to Stamford Bridge in May of the 2015/16 season needing all three points to have a chance of winning a first league title since 1961.
Any other result would hand rivals and underdogs Leicester City a mind-blowing, historic first ever league title.
Spurs took a 2-0 lead with goals from Harry Kane and Son Heung-min before half-time, sending the travelling fans in the Shed End into raptures as the prospect of staying in the title race edged closer.
But that euphoria quickly transformed into dismay in the second half as Spurs lost control of the London derby.
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First, Chelsea halved the deficit through Gary Cahill. Tempers then began to flare as the pressure mounted on the away side to maintain their lead.
Unfortunately for Spurs, Eden Hazard went on to put the final nail in the coffin of Tottenham's title chances, firing in a 83rd minute equaliser.
It was a draw, but it may as well have been a defeat as Hazard's goal won Leicester the title without the Foxes even having to kick a ball.
Nine yellow cards were handed to Spurs in that crushing game - a Premier League record - whilst another three were given to Chelsea.
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Midfielder Mousa Dembele also received a six-match suspension for violent conduct for appearing to eye-gouge Blues forward Diego Costa.
Both clubs had to face three FA charges and they were fined for failing to control their players
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Pochettino learned the hard way that ensuring his players kept their composure against their London rivals may have kept them in that famous title race.
Spurs ended up finishing third that season, with rivals Arsenal finishing in second to make matters even worse.
When Pochettino met Spurs for the first time in November after taking over at Chelsea last summer, Pochettino acknowledged the key lesson he took with him after that night in 2016.
"I learned a lot from the Battle of the Bridge," he said. "I got a lot of criticism after the 2-2 because people said to me it was my fault because I don't teach the player how to control their emotions."
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Pochettino inflicted his former side and Ange Postecoglou's first loss of the season in a wild 4-1 victory on his return.
This time round, he felt it was his side that kept a level head, with Tottenham losing two men to red cards.
Dejan Kulusevski's early opener was cancelled out by half-time, with Cristian Romero sent off and Cole Palmer netting his penalty to level things up.
In the 55th minute, Destiny Udogie was given his marching orders too, with Chelsea's Nicolas Jackson then firing in a hat-trick to make it 4-1.
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"What I can say is this type of game is about tactics, it's about form, the approach of the game and also it's to control the emotion," Pochettino said.
"One thing my players managed well was the control of the emotion. We played 10-12 minutes not in a good way, when we conceded the goal it was a big hit for us and we provided them the possibility to play.
"Then we started to control the game, force them to make a mistake. We play 120 minutes and I think we deserved to win. Crazy but fair. All the decision the VAR was fair.
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"Tell me one decision that was not fair and even a few decision more Tottenham was lucky. When you watch the game again and try to learn from the game, Tottenham was very lucky because they finish with only two less than us."
Pochettino has the chance to be on the right side of another Battle of the Bridge this Thursday, as the two sides go head-to-head in west London, live and exclusive on talkSPORT.