However, Brentford hit back three minutes later through Kristoffer Ajer to register just their second point in seven games.
“We were winning in the end, maybe it wasn’t deserved, but then you have to take the three points,” said Ten Hag. “It is very disappointing to draw the game.”
Spurs have now come from behind to win in four of their last five home games and needed another second-half turnaround after Tahith Chong’s strike put Luton into a shock lead after just three minutes.
An Ange Postecoglou half-time substitution again made an impact for Tottenham as Brennan Johnson’s cross was turned into his own net by Issa Kabore just six minutes after the Welsh international’s introduction.
Son had missed a number of chances earlier in the game but finally got some fortune when his deflected effort trickled past Thomas Kaminski for his 15th goal of the season.
“Until the end I was getting frustrated but I wanted to stay calm as captain,” said Son.
“We don’t want it to always end like this, it could be nicer when we have it (won) earlier.”
Tottenham’s victory briefly took them into fourth, but Villa responded as goals from Moussa Diaby and Ezri Konsa gave them the bragging rights from a Midlands derby.
Chelsea ‘upset’ Pochettino
Chelsea boss Mauricio Pochettino was met with another backlash at Stamford Bridge after his side failed to make the most of an extra man for the entire second half and drew 2-2 against second-bottom Burnley.
The Blues appeared on course to cruise to victory after Lorenz Assignon was harshly sent off for pulling down Mykhailo Mudryk inside the area.
Burnley boss Vincent Kompany was also shown a red card for taking his protests too far.
Cole Palmer coolly chipped in the resulting penalty, but the 10 men levelled two minutes into the second half thanks to Josh Cullen’s super finish from outside the box.
Raheem Sterling had been booed off in Chelsea’s FA Cup quarter-final win over Leicester a fortnight ago but thought he had set up the winner in style with a flick that Palmer stroked into the far corner.
Chelsea, though, failed to hold out again as Dara O’Shea headed in a corner nine minutes from time.
“Today we didn’t show the capacity, the energy, the hunger that is the minimum to compete in the Premier League,” said Pochettino.
“In the defensive phase we conceded too much. That is why I am so upset and disappointed.”
Newcastle fightback
Newcastle closed to within one point of West Ham in seventh after a remarkable fightback to win 4-3 at St. James’ Park.
Goals from Michail Antonio, Mohammed Kudus and Jarrod Bowen wiped out the advantage given to Newcastle by Alexander Isak’s early penalty.
However, a second Isak spot-kick 13 minutes from time sparked the turnaround before substitute Harvey Barnes struck twice to send Eddie Howe scurrying down the touchline in celebration.
“A lot of emotions in that game, we were swinging all over the place,” said Howe.
“The last 10 minutes was amazing to be part of.”
Everton’s winless run stretched to a club record 12 Premier League games after a 2-1 defeat at Bournemouth to leave the Toffees still perilously placed just three points above the relegation zone.
Nottingham Forest edged out of the bottom three, above Luton on goal difference, as Chris Wood salvaged a 1-1 draw against Crystal Palace.
Bottom-of-the-table Sheffield United were denied just their fourth win of the season after conceding twice late on to draw 3-3 with Fulham.
All of the three title challengers are in action on Sunday.
Liverpool have the chance to go top when they host Brighton before Manchester City and Arsenal kick-off at the Etihad in a clash of huge significance in the title race.
© Agence France-Presse
Photo: Twitter @ManUtdPidgin