We seemed all set to make it two wins from two in Group J as we led through Erik Lamela’s first half goal and looked capable of adding a second after the break at Stade Louis II.
However, Monaco levelled when two substitutes combined in the 81st minute, Nabil Dirar crossing for Stephan El Shaarawy to head home from close range.
An away point in Europe is never to be sniffed at though and Qarabag’s 1-0 win against Anderlecht left us top of Group J by a point.
There was a touch of drizzle and a firm breeze within the stadium as we embarked on our first away game of the 2015-16 Europa League campaign.
It was an experienced side fielded by Mauricio Pochettino with two changes at full-back, with Danny Rose and Kieran Trippier returning to the side in place of Ben Davies and Kyle Walker. The only other change from the weekend's win over Manchester City came in attack with Nacer Chadli starting in place of the injured Heung-Min Son.
We started brightly and forced the first good chance inside four minutes when Trippier found space on the right and whipped a dangerous low cross in that was deflected behind for a corner.
It was slow going at times but the next opening came with 20 on the clock. Harry Kane raced onto a Rose through ball and dragged the goalkeeper out wide before laying it back to Chadli, who lobbed an effort onto the roof of the net.
Hugo Lloris was finally called into action midway through the half when Adama Traore hit a low, skidding shot that he saved yet failed to grasp.
With 10 minutes of the first period remaining we broke the deadlock. Lamela finished the move as he scored his third goal in four games and his second in the Europa League this season. Chadli galloped forward before feeding Dele Alli, the youngster’s shot squirming through a number of bodies to Lamela who could scarcely believe his luck as he tapped into an empty net.
What had been a slow game then suddenly burst into life. First Fabio Coentrao squandered a free header before Kane had a shot palmed away after good work from Alli and Lamela again.
Next to miss a gilt-edged header for the home side was the big striker Lacina Traore who also found space at the back post but, like his team-mate two minutes earlier, headed wide.
Traore was a handful with his size and he almost turned in a Thomas Lemar cross as the half drew to a close but Jan Vertonghen did well to stick a toe on the ball and divert it behind for a corner.
The second half started with a better tempo to it than the first and we looked a threat going forwards in the opening exchanges.
Traore squandered a third header which looked arguably the easiest of the three, although he would have been thankful to see the off-side flag go up, which spared his blushes.
Clear-cut chances remained few and far between as Clinton Njie came on for Lamela with 25 minutes to go and Andros Townsend replaced Chadli five minutes later.
Kane saw a shot deflected over the bar and Eric Dier had a header brilliantly saved from the resulting corner. A minute later Trippier sent a great ball in from the right and Kane got his header away well but it bounced comfortably into the arms of the goalkeeper from a good position.
Njie almost sealed it but strayed a yard off-side following a good break led by Kane as things started to get tense with 10 minutes to go.
It looked like we were edging towards a clean sheet but substitute El Shaarawy got his side back on level terms with a towering header from Dirar's cross from the right nine minutes from time.
There was one more serious chance of note but superb defending by Rose denied Guido Carrillo on the follow-up after Lloris parried Dirar’s shot from 25 yards.
Monaco (4-1-3-2): Subasic, Fabinho, Raggi, Carvalho (Dirar 76), Coentrao; Toulalan; Moutinho, A Traore, Lemar (El Shaarawy 60); Silva, L Traore (Carrillo 68). Substitutes (not used): Nardi, Wallace, Bakayoko, Pasalic.
Spurs (4-2-3-1): Lloris (c), Trippier, Alderweireld, Vertonghen, Rose; Alli, Dier; Chadli (Townsend 70), Eriksen (Carroll 90+2), Lamela (Clinton 65); Kane. Substitutes (not used): Vorm, Fazio, Wimmer, Winks.
Goals: Monaco – El Shaarawy 81. Spurs – Lamela 35.
Yellow cards: Monaco - Toulalan.
Referee: Artur Dias.