Tahith Chong's well-worked goal had given the Hatters an early lead, but Spurs responded well and equalised early in the second half when Johnson's cross was turned into his own net by Issa Kabore.

Spurs laid siege to the Luton goal after restoring parity, but a series of crucial last-ditch challenges kept Ange Postecoglou's team at bay - and Alfie Doughty somehow prevented Johnson's close-range effort from rolling over the line.

However, there was nothing Luton could do about Son's 15th goal of the season, which means Tottenham have come from behind to win four of their past five home Premier League matches.

Aston Villa will reclaim fourth place with a draw at home to Wolverhampton Wanderers later on Saturday. Luton, meanwhile, drop into the relegation zone.

Spurs come from behind again

Tottenham's 3-0 defeat at Fulham before the international break was described by Son as a "big wake-up call", but it took Postecoglou's team a while to hit their stride against Luton.

The opening goal was a sloppy one to concede, with Son dispossessed on the edge of the Luton area and Yves Bissouma beaten far too easily by Andros Townsend in the build-up to Chong's crisp finish.

But Spurs were left cursing their luck when Son's shot rattled the inside of the near post, rolled across the goalline, struck the other post and bounced clear - moments after Timo Werner had dragged a shot wide from an excellent position.

In the same move, Werner's follow-up effort was blocked by Kabore before Teden Mengi blocked Pape Sarr's goalbound shot on the line.

Tottenham have now failed to score a first-half goal in six consecutive games, but they were level early in the second half when Johnson - who replaced the ineffective Dejan Kulusevski at half-time - drilled a low ball across the face of goal and Kabore slammed it into his own net.

It seemed only a matter of time before Spurs' relentless pressure would pay off, but when Doughty's last-gasp intervention denied Johnson, Tottenham fans could have been forgiven for thinking it might not be their day.

When the second goal did arrive there was an element of luck about it, but it was a slice of good fortune Son and his team-mates deserved after going agonisingly close on more than one occasion.

Luton's luck runs out

Luton took less than three minutes to extend their club-record scoring run to 18 successive top-flight fixtures, but once again they were unable to retain their advantage.

Rob Edwards' men are just the third side in Premier League history to lose three successive games in which they have led at half-time, after Aston Villa in May 2021 and Sunderland in April 2003.

The visitors even went close to doubling their advantage in the first half, but the retreating James Maddison produced a crucial block to deny Carlton Morris at the near post.

Luton continued to pose a threat on the counter-attack in the second half, with Ross Barkley and Jordan Clark both testing Guglielmo Vicario with low drives from the edge of the penalty area.

Kabore produced several important blocks after putting through his own net, and Kaminski and Doughty combined to keep out Johnson - but Spurs' pressure finally told when Son's shot crept in off the unfortunate Hashioka.

With trips to title-chasing Arsenal and Manchester City still to come before the end of the season, it appears Luton's home form will be key to their hopes of preserving their Premier League status.