Ward-Prowse holds his nerve from the spot

Saints showed enormous character to fight back from 3-1 down with 13 minutes to play, as Theo Walcott pulled one back before Ward-Prowse beat his close friend Fraser Forster with an emphatically taken spot-kick under intense pressure three minutes into added time.

A surreal first half saw both managers forced into two substitutions each, with Rubén Sellés losing both of his starting centre-backs to injury.

Saints ultimately went in at half time a goal down, conceding in the first of seven added minutes to Pedro Porro’s rocket after the Spaniard was afforded too much space on the right flank.

The hosts responded with an equaliser immediately after half time, a close-range finish from Ché Adams, before goals from Harry Kane and Ivan Perišić left Spurs thinking they’d done enough to take maximum points back to North London.

Manager Sellés made three changes for Saints’ third game in seven days, restoring Roméo Lavia, Walcott and Stuart Armstrong to his side – the latter for his first start in three weeks – at the expense of Ibrahima Diallo, Carlos Alcaraz and Kamaldeen Sulemana.

An eventful opening to the game saw a chance at either end and a substitution for both teams inside the first ten minutes.

There was an early warning for Saints when Son Heung-min crept in behind the defensive line, but his attempt to square the ball across goal was fruitless with nobody up in support.

The hosts responded with an attack down the left from which Romain Perraud picked out Stuart Armstrong, who had a free shot from 15 yards but his strike lacked conviction.

When Spurs cleared the ball only as far as Ward-Prowse, the skipper’s scuffed riposte was heading harmlessly wide until Adams redirected the ball goalwards, but the Scot was stretching and unable to find the target from six yards with Forster beaten.

Then came the changes. Richarlison lasted only five minutes, Armel Bella-Kotchap eight, with the defender forced off by what looked to be a recurrence of the shoulder injury he suffered earlier in the season, as Mohammed Salisu took his place.

The high-octane start resumed when Ward-Prowse sent a low left-footer narrowly wide, before Walcott latched on to Mohamed Elyounoussi’s through ball and went one on one with former teammate Forster, whose sprawling save was made academic by a retrospective offside.

Spurs responded with a glancing header from Eric Dier that just flashed past the post from a short corner involving Richarlison’s replacement, Dejan Kulusevski.

Tottenham arrived at St Mary’s having lost their last four away games in all competitions, but their talented front three always carry a threat, regardless of which combination Antonio Conte selects.

Kane and Son might have combined when Kane broke free in the inside-right channel, but the skipper opted to go alone and uncharacteristically blazed over.

Then Son fizzed a ball across goal collected by Porro, who picked out the same fan in the crowd as his captain.

Kulusevski, meanwhile, attempted to present Kane with a tap in, only for Lavia to intercept, almost scoring an own goal in the process.

The club-record goalscorer was lurking with intent again when found in the box by Ben Davies, but the pass was just behind the striker, allowing Salisu the split second he needed to recover and block Kane’s eventual shot.

A confusing half shaded by the visitors ended with four enforced substitutions when Jan Bednarek and Davies also limped off, replaced by Ainsley Maitland-Niles and Perišić respectively, with Maitland-Niles forced to partner Salisu in central defence.

Son has struggled to hit the heights that saw him share last season’s Premier League Golden Boot with Mohamed Salah, but he did send a low drive skidding just past Gavin Bazunu’s left-hand post as the keeper dived full length.

Instead the Korean would have to settle for an assist for Porro seconds after the fourth official signalled seven added minutes.

Spreading the play from left to right, Son’s low pass invited the Spaniard to surge into the box unopposed, crashing a shot in off the underside of the crossbar to leave Bazunu helpless.

Having conceded just before half time, Saints scored straight after it. Less than a minute had elapsed when Lavia’s piercing pass sent Walcott racing down the right, crossing low for Adams to prod home from no more than four yards, just in front of the despairing Forster.

The goal gave Saints, and the home crowd, a palpable lift. Kyle Walker-Peters flashed a ball across the box before Ward-Prowse’s cross struck an arm, giving the talisman another opportunity to equal David Beckham’s Premier League free-kick record.

However much he’d love to have done it by beating his best mate Forster, it wasn’t to be. The offence occurred just on the limit of his shooting range, and his strike was never dipping in time to find the net.

Spurs were yet to threaten since the interval, but VAR did consider an optimistic penalty appeal when Perišić fired a shot against Maitland-Niles, but it clearly cannoned into his midriff.

That could hardly be considered a let off for Saints, but they were a touch fortunate not to be punished for backing off Kane for too long, inviting the England man to shoot from 20 yards, but again he was off target.

It’s a dangerous game to keep giving him chances, and five minutes later Kane had his goal, rising highest at the far post to head home Kulusevski’s cross from the right, having peeled away on to Walker-Peters and Maitland-Niles as Saints rued the absence of a natural right-sided centre-back.

Sellés turned to his bench to use up his three remaining substitutes in one go with 20 minutes left, introducing the attacking trio of Carlos Alcaraz, Kamaldeen Sulemana and Sékou Mara for Armstrong, Elyounoussi and goalscorer Adams.

Within four minutes, though, Saints were stung by Spurs’ third, as Perišić ruthlessly dispatched a bouncing ball inside the penalty area, driving his shot down into the turf and up into the net, out of reach for the beaten Bazunu.

Just as Saints may have looked beaten, they hit back once more. There was also time for Forster to produce the save of the match in the three minutes between the goals, tipping over a 25-yard piledriver from Maitland-Niles, high to his left, before Walcott pounced to score his first goal in nearly two years, slotting home from the edge of the six-yard box.

St Mary’s had its buzz back, as the exciting Kamaldeen surged into Tottenham territory, finding Mara who was denied by the smothering Forster.

Time was running out but Saints never lost belief and got their reward when Pape Sarr’s wild swing of his right boot caught Maitland-Niles in the box, prompting Ward-Prowse to hold his nerve with an emphatic penalty, high to Forster’s left.

A breathless finish saw Clement Lenglet threaten an even later winner for the visitors, but the Frenchman headed wide with the last touch of a memorable contest.