It was only a 1-0 loss but Jose Mourinho's backups failed to fire and even Heung-Min Son and Harry Kane couldn't save them when they arrived off the bench.
Next up is a home game against Brighton, and it's at their new stadium where they have struggled to get wins this campaign.
Spurs lost to Everton, drew 1-1 with Newcastle, and then saw London rivals West Ham come from 3-0 down to draw 3-3 in N17.
Had it not been for those three results, Mourinho's men would be sitting pretty at the top of the Premier League table.
But they can't dwell on it and must now focus on facing their south coast opponents.. Mourinho was furious with his players and will want a vast improvement against Brighton
The Seagulls have only won one match this season and have put in mixed bag of performances under manager Graham Potter.
But, under the former Ostersunds boss, the Seagulls side gave Tottenham plenty of problems last year.
They won 3-0 last October in one of the matches which eventually spelled the end for Mauricio Pochettino in north London, while on Boxing Day Spurs may have won 2-1 but it was very much a lucky escape.
And ahead of Sunday's clash, Mourinho just wants a good performance.
"I am not so worried about the home record," Mourinho said. "I am worried about playing well and getting points and against Everton the frustration was we probably deserved, I think, a point but we didn't play well and in other games the feeling was different.
"We played very well against Newcastle, we played very well against West Ham so let's try and play very well against Brighton and when you play very well you normally win, so let's try."
Tottenham team news
With Spurs able to almost totally rotate their team in midweek, there aren't any new fitness worries for Mourinho.
Ndombele missed the trip to Belgium so he could get some rest and he will almost definitely return.
The likes of Dele Alli, Giovani Lo Celso, Steven Bergwijn, and Carlos Vinicius will all drop out of the first-team after they were substituted at half-time, while Gareth Bale is unlikely to start either.
Defender Japhet Tanganga is the only confirmed absentee.
Tottenham predicted line-up
A Europa League loss to Royal Antwerp has brought Tottenham back to Earth with a bump.