Goals from Bernardo Silva and Thomas Lemar put the Ligue 1 side two goals up after half-an-hour before defender Toby Alderweireld headed the hosts back into the match just before half-time.
The second half saw Spurs turn up the pressure but they failed to break down the Monaco back line before Mauricio Pochettino replaced Eric Dier with Sissoko in one final throw of the dice.
The former Newcastle man barely got a touch during his cameo though he was almost played through on goal by Vincent Janssen but Monaco keeper Danijel Subasic was quick off his line to collect.
Sissoko cost Spurs £30m on transfer deadline day but he has failed to make an impact for his new club so far as his match fitness remains in question as he's not started a competitive match since the Euro 2016 final.
The French international was eager to force through a move to a Champions League club following Newcastle's relegation from the Premier League last term and on transfer deadline day, Tottenham granted his wish.
The 27-year-old has made two brief substitute appearances so far as he looks to get back to full fitness.
Still, Newcastle fans were eager to comment on their former players impact - or lack thereof. THEY HAMMERED HIM!