Tottenham Hotspur face requiring just their second ever win in Italy after Jose Maria Basanta's equaliser gave Fiorentina a narrow advantage after the first leg of the Europa League last 32 tie at White Hart Lane.
Roberto Soldado put Spurs ahead after just six minutes with a bullet volley but Hugo Lloris's handling error allowed Basanta to level before the break.
Soldado was denied by goalkeeper Ciprian Tatarusanu and Nacer Chadli hit the bar as Tottenham pressed for a lead to take to Florence but it wasn't to be and it could have even been worse had Mohamed Salah and Mario Gomez not been off-target with second half efforts.
Spurs have just one European away win in Italy, against AC Milan in 2010, and they'll require heroics similar to the performance produced five years ago to maintain their interest in the second tier continental competition.
Despite being able to call on a fully fit squad for the first time this season following a rest over FA Cup fifth round weekend, Pochettino opted to leave out top scorer Harry Kane while Erik Lamela and Mousa Dembele were both omitted.
La Viola were without Juan Cuadrado after his £23.3m move to Chelsea in January, but the Blues' on loan winger Salah led a team including fellow former Premier League players David Pizarro, Stefan Savic and Borja Valero.
Both sides had impressed since reaching the knock-out phase, with Fiorentina unbeaten in their last eight and keeping in touch in the race for the top three, while Spurs had recorded home wins against Arsenal and Chelsea and also reached the League Cup final.
And it was the home side who showed greater evidence of that recent form in the early moments and they surged ahead after just six minutes as Christian Eriksen's corner was hammered home on the volley by Soldado.
The Spaniard's first goal for over two months came at the opportune moment for the ex-Valencia forward and the return of his confidence appeared instantaneous as he attempted an overhead-kick minutes later which was gathered gratefully by Tatarusanu.
The Italian giants were merely consigned to surviving in the first half in north London, with Mario Gomez painting a forlorn figure at the pivot of the Fiorentina attack.
But out of nothing the 1990 Europa League runners-up grabbed a critical away goal with their first genuine attack as Matias Fernandez's free-kick caught out Hugo Lloris, whose saved rebounded off Savic and fell the way of Basanta who tucked home with a cushion volley.
Though the momentum was now with the visitors it did not prevent Tottenham fashioning two golden chances to level on the brink of half time as Tatarusanu first kept out Soldado's flicked header before Nacer Chadli's follow up hit the bar and bounced agonisingly short of the line.
Salah almost had Fiorentina ahead on the night two minutes after the break but his swept shot bounced wide as Lloris scrambled across his goal and as Tottenham toiled at the other end Soldado's wayward flicked header barely troubled Tatarusanu's goal.
Pochettino took until the 65th minute to introduce Kane, who replaced Chadli to the joy of the home crowd who were growing increasingly frustrated at the drop of intensity from the first half and Gomez almost compounded that but lashed over after turning past Kyle Walker.
Amid a raft of changes, which also saw Erik Lamela introduced, neither side were able to secure the crucial third goal of the night to take a lead into the second leg in seven days time, with both teams playing out a stalemate in the north London rain.