Spurs were well-fancied to secure their second win of the season on the back of their 2-2 draw at Manchester City last week as Newcastle arrived having lost their opening two matches against Arsenal and Norwich respectively.
However, despite losing Allan Saint-Maximin to injury early on, the Magpies took the lead through record-signing Joelinton just before the half-hour mark.
Spurs huffed and puffed in search of an equaliser, but they failed to negotiate their way past a stubborn Newcastle defence as the visitors survived a late onslaught in six minutes of stoppage time to secure their first three-point haul of the new season.
Mauricio Pochettino made two changes for Spurs, Heung-min Son returned from suspension in place of Christian Eriksen, while Lucas Moura came in for injured record signing Tanguy Ndombele.
Steve Bruce also made two changes to his Newcastle starting XI from the 3-1 reverse at Norwich as Sean Longstaff replaced Jonjo Shelvey and Saint-Maximin returned in place of Ki Sung-yueng.
Spurs enjoyed all the early possession in the baking hot sunshine, but never really imposed themselves on the Magpies’ backline, while the visitors’ forward Saint-Maximin lasted just over 15 minutes before being replaced with what looked like a hamstring problem.
It was Newcastle who had the first attempt of note on 23 minutes when Joelinton picked the run of Longstaff who watched as Hugo Lloris parried his effort over the crossbar.
Spurs failed to take heed of that warning as the Magpies took the lead with their next attack on 27 minutes. Substitute Christian Atsu’s ball found Joelinton unmarked in the middle of the area and the Brazilian coolly picked his spot with a low left-foot drive beyond the dive of Lloris.
It took Spurs until the 32nd minute to test Martin Dubravka as the Slovakian keeper pushed a Son volley at the far post, before the South Korean dragged an effort well wide on 40 minutes.
Spurs tried to up the tempo after the break, while they were forced into a change as Kyle Walker-Peters picked up an injury and was replaced by Eriksen.
Newcastle continued to hold firm and escaped a Video Assistant Referee review on 79 minutes when Jamaal Lascelles appeared to lose his footing and threw himself into the path of Harry Kane inside the area, but the penalty was not given despite the Spurs man being knocked to the ground.
Moura should have equalised for Spurs on 81 minutes when Moussa Sissoko put the ball on a plate for him from the right but he somehow shot over the bar with the goal at his mercy.