Mame Biram Diouf headed home a late equaliser as Tottenham threw away a two-goal lead to draw 2-2 at home to Stoke.
Spurs, who lost both league games against the Potters last season, looked on course to secure their first three points of the campaign after first-half goals from Eric Dier and Nacer Chadli had given the hosts a commanding advantage.
Stoke, however, came storming back with Marko Arnautovic converting a 78th-minute penalty before Diouf headed in seven minutes from time to complete an unlikely comeback.
Scrutiny is likely to be placed on Mauricio Pochettino's substitutions after the Tottenham boss replaced both Harry Kane and Ryan Mason in the second half.
The changes seemed to stifle the home team's momentum and there was a smattering of boos from the White Hart Lane crowd at the sound of the final whistle.
It represented a marked contrast from the feeling of optimism at the start of the afternoon when the home fans had cheered the presentation of Tottenham's five summer signings, including Lyon's Clinton Njie, whose arrival was confirmed on Saturday morning.
Tottenham dominated possession early on and Jack Butland had to twice deny Christian Eriksen in the opening 10 minutes, pushing behind the Dane's driven shot and then his whipped free-kick from the edge of the box.
Hugo Lloris returned to the Spurs starting line-up after recovering from a wrist injury to make his 100th appearance for the club, but the Frenchman's rustiness nearly cost his side as he gifted the ball to Diouf before saving the striker's angled finish.
Stoke appeared to be finding their feet but in the 19th minute the visitors were undone in the simplest of fashions as Eriksen fired a corner to the near post and Dier shrugged off Marco van Ginkel to head in Tottenham's first goal of the season for the second year running.
Kane had struggled for his usual influence in the early stages but the striker came to life at the end of the half, first seeing an emphatic finish ruled out for offside before providing a superb reverse pass into the path of Mason, whose shot was blocked by Butland at close range.
On the brink of half-time, however, Tottenham did find a second and Kane was involved again, playing in Ben Davies down the left, who looped a cross to the back post for Chadli to slot home.
Tottenham remained in the ascendancy at the start of the second period and Kane should have opened his account when Chadli found him unmarked but the finish was again saved by Butland.
Kane was substituted for Erik Lamela and Stoke enjoyed a better spell as the contest moved past the hour mark, with Diouf again thwarted by the quick reactions of Lloris, who denied the Senegalese' header.
Finally, the visitors found the goal they deserved as substitute Joselu was wrestled to the ground by Toby Alderweireld in the area and, with referee Robert Madley pointing to the spot, Arnautovic stepped up to slam the ball past Lloris.
Spurs seemed to have lost all control of the contest and five minutes later, their lead was cancelled out as a neat exchange between Arnautovic and Stephen Ireland allowed the latter to cross for Diouf, who this time headed in the equaliser.
It could have got even worse for Tottenham when Ireland and Diouf both went close to snatching victory but there was to be no more late drama as the spoils were shared.
TWEET OF THE MATCH
"Stoke to win in last 3 mins same old Spurs" - Lord Sugar is nearly right.
Hugo Lloris: 7 (out of 10)
Kyle Walker: 6
Toby Alderweireld: 6
Jan Vertonghen: 6
Ben Davies: 7
Eric Dier: 8
Ryan Mason: 7
Mousa Dembele: 7
Christian Eriksen: 8
Nacer Chadli: 8
Harry Kane: 7
Erik Lamela: 6
Nabil Bentaleb: 6
Jack Butland: 8
Glen Johnson: 6
Geoff Cameron: 6
Marc Muniesa: 6
Erik Pieters: 7
Glenn Whelan: 7
Marco van Ginkel: 5
Jonathan Walters: 6
Ibrahim Afellay: 6
Marko Arnautovic: 8
Mame Biram Diouf: 7
Stephen Ireland: 7
Charlie Adam: 6
Marko Arnautovic: Arnautovic caused problems for Tottenham right back Kyle Walker throughout the match and he was involved in both of Stoke's goals, coolly converting a penalty in the 78th minute before playing in Stephen Ireland, who assisted Diouf's all-important equaliser.
MOMENT OF THE MATCH
Mame Biram Diouf: Diouf had to wait for his moment of glory as he had seen a number of efforts saved by Lloris but the Spurs keeper could do nothing to prevent the Senegalese nodding home with seven minutes to play, completing a remarkable comeback for the visitors.
VIEW FROM THE BENCH
Mauricio Pochettino will perhaps look back and regret taking off both Kane and Mason, which seemed to knock the momentum out of his players and remove all the hosts' confidence. Mark Hughes, in contrast, will be delighted with his replacements as Joselu won the penalty and Ireland provided the cross for the equaliser.
MOAN OF THE MATCH
Tottenham fans had begun the afternoon full of optimism, peaking in at the work on the new stadium next door and cheering the five summer signings, who were presented on the pitch before kick-off. There was, however, a smattering of boos at the full-time whistle, marking the home support's disappointment with their side's capitulation.
WHO'S UP NEXT
Leicester v Tottenham (Premier League, Saturday August 22)
Norwich v Stoke (Premier League, Saturday August 22)