But Spurs owe a big thanks to Magpies captain Jonjo Shelvey, as his brainless 48th minute red card proved costly. Up until that moment, Newcastle had matched and frustrated Mauricio Pochettino's side.
The remainder of the contest was academic. The only disappointment for Spurs was Harry Kane's failure to open his account despite having more than one presentable opportunity.
But Tottenham more than deserved their win and here are the five things we learned from Spurs' victory at St James' Park.
No signings, no problem
Much has been made of Spurs' lack of transfer business this summer – they are the only Premier League club yet to sign a single player – but there is little doubt their current crop is good enough to launch another title push.
And, more importantly, on the basis of the 90 minutes at St James' Park, the Spurs players remain motivated to go one better than they managed last season.
Yes, they were given a huge helping hand when Newcastle were reduced to ten men just minutes into the second half, but Pochettino's side had been in control of the game from the opening whistle.
They dominated possession, ending with 73 per cent of the ball, were defensively resolute and quickly took advantage following Shelvey's dismissal. Alli's goal was superbly worked, as was Davies'.
Rafa's Newcastle Won't Be A Soft Touch
In their recent Premier League campaigns the Magpies have far too often been easy to beat. But Benitez, unsurprisingly, won't let that be the case this term.
Newcastle were well organised, despite losing two of their starting back four inside the first half, and frustrated Tottenham for large spells of the contest.
Benítez's side may not have offered a great deal going forward – they didn't register a shot on target in the opening 45 minutes – but then they were up against a Spurs defence which was the best in the top flight last season. So it wasn't a huge surprise.
However, there were enough signs that suggested against weaker opposition Newcastle should be able to take greater risks going forward without weakening their defensive structure.
And that should be enough to ensure they do not become embroiled in yet another relegation battle.
Kyle Walker-Peters Stepped Up
With Kyle Walker sold and Kieran Trippier injured, Pochettino had a selection headache at right-back. He either had to play a senior player out of position or turn to yet another of Spurs' youth prospects.
Given the Argentine's record, it was hardly surprisingly he chose the latter option and handed Walker-Peters his first start in a Tottenham shirt. It was a bold move but the youngster stepped up and proved himself more than capable of performing in the top flight.
Walker-Peters, who was part of the England Under-20 side who won this summer's World Cup, had one scare in the first half when he bundled into Dwight Gayle in the penalty area but, fortunately for the right-back, the striker was offside.
It was the only blot on Walker-Peters copybook. He restricted the tricky Christian Atsu well for the remainder of the contest and was confident in possession.
Walker-Peters ended the game having made three successful tackles, a team high, three clearances and one block. He couldn't have hoped for a better debut.
Bigger tests will come, especially if he retains his place for the visit of Chelsea next weekend. But his debut was one that suggested Tottenham do not have to enter the transfer market for a right-back. Trippier and Walker-Peters should be enough.
Moussa Sissoko Fails to Impress
Since leaving Newcastle for Tottenham 12 months ago, the Frenchman's career has nosedived. He made just eight Premier League starts last season and many expected Sissoko to leave north London this summer.
However, after producing a couple of impressive performances in pre-season, Pochettino handed the 27-year-old a start against the Magpies. It was a lifeline that Sissoko had to take.
And, while he wasn't desperately poor, there was nothing to suggest Sissoko should be a regular starter in this Tottenham side. He lasted 57 minutes before being brought off for Heung-Min Son, and the Korean immediately livened up the Spurs attack.
Sissoko just doesn't fit in alongside Alli, Harry Kane and Christian Eriksen. He doesn't have the speed of thought or nuanced technique to exchange quick passes in and around opposition penalty areas.
He did, however, protect Walker-Peters well in the opening 45 minutes, which you expect Pochettino would've demanded and appreciated.
Shelvey's immaturity remains
There is little doubt Shelvey is a gifted midfielder. He possesses technique and vision that many a Premier League player would love to have. However, his temperament is often questioned and rightly so.
The red card he was shown against Spurs was stupid and naive. A nothing collision with Alli resulted in a Newcastle free-kick. The Tottenham star was unhappy with the call and nudged the ball away from Shelvey.
As the Magpies captain went to collect, he deliberately stepped on Alli's ankle in front of referee Andre Marriner. A red card was rightly shown and Newcastle had to play the remaining 40 minutes with ten men.
Eventually Tottenham found a way through, with Alli poetically scoring the opening goal. Would they have done so if Shelvey remained on the field? We'll never know but they would've stood more of a chance.
Last season Shelvey was booked ten times and sent off once. He also served a five-match ban and was fined £100,000 after being found guilty by the FA of using abusive and insulting words to an opponent..
Now 25 years old, his petulance can't and won't be accepted Benitez. Back in the Premier League the Spaniard needs players that can be trusted, Shelvey will have to prove himself on his return.