Southampton came from behind twice to edge a thrilling Premier League clash against Tottenham courtesy of Che Adams' headed winner.
The visitors bagged two goals in three minutes late on to turn the game completely on its head after Spurs looked to have done enough.
Cristian Romero's diving header was disallowed early on but it didn't take long for Spurs to grab the opener, as Jan Bednarek prodded Pierre-Emile Hojbjerg's cross past his own keeper after 18 minutes.
Southampton reacted well and equalised just five minutes later, Armando Broja capitalising on a catalogue of errors at the back to sidefoot Romain Perraud's cross beyond Hugo Lloris.
It was the visitors who were in control for the opening 45 minutes, but the half-time jeers from Spurs' fans clearly had an impact.
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Spurs emerged from the second half a different side and when Lucas Moura whipped a delicious cross across the face of goal for Son Heung-min to finish it seemed as though there was only going to be one winner.
But Southampton refused to give in and got what they deserved when Mohamed Elyounoussi headed them level, before Adams produced an almost carbon copy goal moments later.
Steven Bergwijn then looked to have rescued a point for Spurs at the death only for his effort to be ruled offside following a VAR check as Southampton snatched all three points.
Here are the talking points from the Tottenham Hotspur Stadium.
1. Rolls Royce Romero
Say it quietly, but Spurs might actually have a proper defender on their hands here.
Much has been made of Romero's showing in the FA Cup win over Brighton at the weekend, but the Argentine centre-back proved it was no fluke by following it up with an individual all-round display of the highest order.
Towering in the air, composed on the desk, he's capable and confident enough to carry forward into space or split opposing lines with his passing - which almost released Son early on.
He had the strength to muscle Che Adams off the ball with ease, started attacks from deep and patrolled the back line as best he could, which was a task unto itself.
Romero even had the whole of the home crowd up on their feet when his diving header looked to put Spurs in front, only to be denied by the offside flag.
It's little wonder he cost close to £50m - and he's here to stay.
2. Shaky Spurs
While Romero looks the real deal, Spurs could do with a couple more like him to slot alongside him.
If you were to pinpoint the weaknesses in Conte's lineup it is at the back and down the right flank defensively, where Southampton got plenty of joy..
Emerson Royal is not the answer at right wing-back, and Spurs are in need of an upgrade on Davinson Sanchez.
The first equalising goal typified Spurs' defensive performance, really, often looking vulnerable against a Southampton attack which, in reality, shouldn't have caused them as many problems as they did.
Few can blame Ben Davies for his unfortunate slip, but there was no conviction from Spurs' defence in reacting.
Royal didn't do enough to stop the cross, Sanchez had left Broja unmarked, and just like that it was 1-1.
It was Royal who was closest to Southampton's second goal, though it was Harry Winks who had let his runner go., before Royal then left Adams unmarked to nod home the crucial winner.
Spurs had sat deep throughout as a precaution, doing their best to minimise any risk, suggesting Conte is well aware where his side's weakness lies.
3. Conte confusion
One thing you can say about Tottenham at the minute is that they are entertaining.
But boy do they need some work.
Conte's insistence on playing wing-backs pretty much reduced his side to mainly counter attacks in the first half as they were pegged back by Southampton into a 5-4-1 of sorts.
Not the worst idea, given Tottenham's deadliness on the break, but it left them chasing shadows, and not quickly or effectively enough.
Spurs simply don't have the personnel to carry out Conte's blueprint at present.
They were largely second best on their own patch and probably could have been a few down at half-time, hence why they were booed off at the break by their own fans.
The hosts were happy to leave gaps in front of their own defence - a problem arguably made from Winks and Hojbjerg being outnumbered and pulled from pillar to post by Saints' passing game.
Sanchez would step into the gap at times but was frequently left in no mans land, and it was through that window that Broja was able to sneak in behind and almost put Southampton in front.
On the whole it was erratic and Spurs trod a thin tightrope, which eventually buckled.
Conte wants better players to fit his system, but at the minute it's square pegs in round holes.
4. Super Saints
For all Tottenham's issues, take nothing away from Southampton.
The visitors came to London and dominated the match, spraying the ball around at will, pressing their opponents all over the park and generally making life difficult for them - before breaking their hearts late on.
Harry Kane was reduced to just a few notable touches. Southampton were first to every ball and carved a number of openings, with Hugo Lloris pulling off two excellent saves at full stretch.
They would have been disappointed to go back to St Mary's with nothing to show for it, or even a point and fully deserved their victory.
Some wasteful finishing almost cost them, Broja got the goal but missed two sitters.
Fortunately his teammates bailed him out.
5. Change is in order
Spurs were much improved at the start of the second half (they had to be). Conte had clearly given them a rollicking at half-time and it garnered a greater sense of purpose from his men.
Winks managed to get on the ball a bit more early on and Tottenham got on top of possession more than they had done, with Kane starting to pull strings.
Conte soon dragged off Hojbjerg - who had a night to forget - and brought on new signing Rodrigo Bentancur in his place. That made an immediate difference.
Bentancur brought a calm presence to the midfield, collecting the ball from his centre-halves and looking to get his side playing.
Moura burst into life too, and you got the feeling a goal would come if Spurs could just find that final ball - one the Brazilian expertly delivered on a plate for Son to restore their lead.
Sadly for Conte, it couldn't last and they couldn't hang on, as defensive lapses cost them - and will harm their top four chances if not eradicated soon.
