Tottenham battled past Southampton in a thrilling FA Cup fourth-round replay to set up a home tie against Norwich City.
Spurs went ahead when Tanguy Ndombele’s shot deflected in off visiting defender Jack Stephens, before Shane Long made it 1-1 after Nathan Redmond’s effort had been parried by Hugo Lloris.
Danny Ings curled a shot past Lloris to put the Saints ahead, but Lucas Moura equalised with a strike from 18 yards.
Spurs won the tie when Son Heung-min converted an 87th-minute penalty.
He had been fouled by Southampton goalkeeper Angus Gunn after a fine pass from substitute Dele Alli had created the opportunity.
For the Saints, midfielder James Ward-Prowse was carried off on a stretcher in the first half with a knee injury.
Spurs will host Norwich, bottom of the Premier League, in round five in a midweek match to be played on 3, 4 or 5 March.
Spurs have to dig deep again
The FA Cup represents Tottenham’s best chance this season of winning their first trophy since 2008 – as they sit fifth in the Premier League, went out of the Carabao Cup at League Two Colchester in September and face a tricky Champions League last-16 tie against an RB Leipzig side second in Germany’s Bundesliga.
They had to come from behind in the third round to force a replay against Middlesbrough before going through, and had to dig deep again here, with two goals in the final 12 minutes to see off a gallant Southampton side.
Unlike Liverpool – who beat Shrewsbury 1-0 with their Under-23 side in a fourth-round reply on Tuesday – Tottenham named a strong side for a match taking place during their two-week mid-season Premier League break.
Boss Jose Mourinho was, though, without the injured Giovani lo Celso and Erik Lamela, plus the ineligible Steven Bergwijn, while Alli was only on the bench after he picked up a knock during last Sunday’s 2-0 league win over Manchester City.
Despite having 24 hours less to prepare than Southampton, the hosts went ahead when Ndombele’s effort, which appeared to be going wide, took a big deflection off Stephens to wrong-foot Angus Gunn.
Mourinho would have been unhappy with Lloris as he could only parry the ball into Long’s path for him to equalise from eight yards out.
But the France goalkeeper made amends in the second half with an excellent reflex stop to turn Jannik Vestergaard’s close-range header over the bar as both sides pushed for a winner.
The Saints looked as if they had it when Ings scored following a fine run from Nathan Redmond but the lead only lasted six minutes before Moura made it 2-2.
Alli’s excellent pass released Son – and after he was brought down by Gunn, the South Korean converted the penalty to take Spurs into the last 16 in dramatic fashion.