Jose Mourinho has given Tottenham the belief they can now beat anyone, but that inner resolve will be tested to the full when his side face Premier League champions Liverpool in a top-of-the-table clash at Anfield on Wednesday night.
Mourinho travels to Merseyside with his Tottenham team sitting top of the Premier League, albeit only on goal difference from Liverpool, and unbeaten in the league since an opening-day defeat at home to Everton.
That underwhelming 1-0 loss prompted suggestions that Mourinho's tactics were outdated, while the Portuguese himself even calling out some of his "lifeless" players for their "lazy pressing".
Fast forward three months, though, and Spurs are now in top spot on the back of the longest unbeaten run in the top flight as the 'Special One' attempts to end the north London club's 60-year wait for the title.
So how has Mourinho transformed a team who were in the bottom half of the table and on a five-game winless streak when he replaced Mauricio Pochettino last November, to one now challenging for the title and believing they can end Liverpool's record-breaking 65-game unbeaten home league run?
New arrivals bring new belief
Mourinho recruited well in the summer, identifying those areas of the team that needed strengthening and addressing them.
In came Matt Doherty and Sergio Reguilon, two modern-day full backs, while despite much eyebrow-raising that greeted his arrival from Southampton, Pierre-Emile Hojbjerg has added much-needed beef to the Spurs midfield.
And despite only limited starts so far while he builds up his fitness, the on-loan Gareth Bale could still have a key role to play in the second half of the season.
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Trial-by-fire methods still work
However, as Sky Sports' Adam Bate explains, Mourinho has also extracted better displays from many of the players already at the club.
"The more striking change under Mourinho has been in the performances of the key players already at the club," he said. "Heung-Min Son is the joint-second top scorer in the Premier League. Harry Kane has become even more complete than before. Tanguy Ndombele has turned it around.
"The assimilation of Ndombele, Tottenham's club-record signing, is a major accomplishment for Mourinho because had he failed to make this work it would have been interpreted as further evidence that his particular brand of man-management no longer worked.
"His trial-by-fire methods had become viewed as outdated, apparently no longer resonating with the modern player. For all the talk of a new Mourinho, and he has taken on younger staff, the suspicion was that he would not be able to reinvent himself. The die was cast."
Defence wins championships
As the old maxim goes, defence wins championships and statically speaking, under Mourinho, Tottenham now have the best defence in the Premier League having conceded just 10 league goals so far this season.
Meanwhile, the form of France No 1 Hugo Lloris has also been instrumental in the club's parsimonious defence, with only West Brom's Sam Johnstone preventing more goals based on the Expected Goals metric.
All of which means Spurs have found themselves trailing for a league-low 50 minutes in total this campaign, which is exactly the way Mourinho wants it.
Mourinho has made the Spurs players believe
As the results improved, with Tottenham having not lost since the opening day of the season, so too did the players' confidence in Mourinho's tactics, especially against their title rivals.
In recent weeks, Spurs have won 6-1 at Old Trafford, normally a graveyard for the north Londoners, beaten both Man City and Arsenal 2-0 at home and left Stamford Bridge with a creditable goalless draw.
And it is those kinds of impressive performances that have got the players believing in Mourinho, according to Gary Neville.
"The players are buying into it, he [Mourinho] has given them belief, they can now handle and play in big matches this team, they look experienced, wise, cute, a little bit nasty," said the Sky Sports pundit on the Gary Neville podcast.
"We have seen them against United, City, Chelsea and Arsenal and they have picked up 10 points out of 12 and he has some really top players and he now feels he can compete with Pep [Guardiola] and [Jurgen] Klopp.
"I think he has got a chance as there is no doubt City and Liverpool are not where they were.
"There are just some little things that are going against them that have not gone against them in the last couple of years.
"And the same with City and that makes it interesting and Tottenham are just looking at them and thinking: 'They are not right and we are OK here, we are just starting to hit form and spirit and we are getting closer to them.'
"And the fact they are getting closer to them and they are not right is giving confidence to them. The top two have set a bar that I've never seen before, none of us have ever seen before in the last couple of seasons, and now we are seeing something that is more normal."
'Jose has a plan on how to win the league this season'
Interestingly, Mourinho takes Tottenham to Anfield exactly two years to the day his United side lost 3-1 to Liverpool, an uninspiring defeat that ultimately proved to be his final game in charge of the club.
In many ways, that unadventurous display was the straw that broke the camel's back for Mourinho at Old Trafford, contrasting so starkly as it did with how United's great rivals performed on the day.
Mourinho's United had also produced a similarly negative performance in a goalless draw at Liverpool in October 2016 which sticks in Neville's mind.
"I recall a game when he was United manager against Liverpool, and I came away thinking that I couldn't watch United playing this way," said the former United captain on Monday Night Football in October.
"Mourinho effectively went with a back six and it was desperate to watch. I went away thinking 'United need to have more than that'.
"I know Liverpool were the better team and United were in a dip, but they had to bring more than that. It didn't feel very innovative or modern. The problem with that is that United couldn't get their counterattacks going when the two wide players were so deep. Jose played a non-dominant style of football."
But the Portuguese has now evolved that very same tactic with great success in order to get results against his title rivals in one-off games this season.
"He still wants the defensive stability," Neville said. "He still wants the clean sheet, and I don't think he wholly trusts his back four at Tottenham, but you look at this Spurs team now, with Moussa Sissoko and Hojbjerg screening, and you've still got a back six [as he had for United against Liverpool], but there are big differences.
"Firstly, the position of Kane is a lot deeper to Zlatan Ibrahimovic into a place that's difficult to pick up. Secondly, and the most important thing, is that Son and [Steven] Bergwijn are near to him.
"Rather than the two nearest players to Zlatan being [Ander] Herrera and [Paul] Pogba - the two central midfielders - now Jose has the right players still in advanced positions to counterattack quickly.
"It's a subtle change, but it's the same system as before in a different way. It is far more palatable and it's easier on the eye, as you've still got the attacking players in attacking positions. Jose has adapted, and he's got the balance of being good defensively with the threat on the counterattack.
"I feel he has to play this way to have a chance of winning the title because I don't think his back four is strong enough without two players beefing it up. They will be a massive threat to most teams and Jose has a plan on how to win the league this season.
"The challenges might come against teams that drop off against them, where they have to be a little bit more creative, but that's when the likes of Kane and Gareth Bale will come into it.
"I don't think he can win it by being proactive against Liverpool, Manchester City and other teams, but if Tottenham buy into it, the players buy into it, it feels like something that's innovative. It's still defensive-minded, but it's got a real threat to it, and they're scoring goals as well."
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Mourinho's greatest challenge
Now the master tactician takes his Tottenham team to Anfield to face their greatest test so far this season against the Premier League champions at a ground where they have won just twice in 28 Premier League visits.
Mourinho's sides, as discussed above, like to score first in games and then control the match, while trying to catch their opponents out on the counter as they look to get back in the contest.
Key to that plan, of course, is the attacking partnership of Kane and Son, who combined for Spurs' opener at Crystal Palace on Sunday, the 12th Premier League goal the duo have fashioned between thems this campaign.
If the pair link up again at Anfield on Wednesday, they will equal the Premier League record set by Alan Shearer and Chris Sutton in Blackburn Rovers' title-winning season of 1994-95.
And who would bet against that happening given the champions' injury-ravaged and at times uncharacteristically porous defence this season - a back line that could feature the inexperienced Nat Phillips at its heart on Wednesday - coupled with their fondness to play a high line against the visitors' pacy forwards?