A deflected strike from Federico Bernardeschi cancelled out Nacer Chadli's first-half penalty as Fiorentina and Tottenham drew 1-1 in the first leg of their last-32 tie in the Europa League.
Tottenham opened the scoring in the 38th minute at the Stadio Artemio Franchi when a foul on Ben Davies offered Chadli - on spot-kick duties with Harry Kane on the bench - the opportunity to score his fifth goal in his last seven games.
However, Mauricio Pochettino's side - showing six changes from the team that triumphed 2-1 at Manchester City on Sunday - were denied an eighth straight win in all competitions by Bernardeschi's fortunate long-range effort that found the net via a flick off Ryan Mason's boot.
Still, a draw on their travels puts Tottenham in pole position to qualify for the next round when they host the return leg at White Hart Lane against the team that knocked them out of Europe at the same stage last season.
A 2-0 defeat in Florence, with goals from Mohamed Salah and Mario Gomez - who have both since left the Serie A club - saw Tottenham defeated 3-1 on aggregate just under a year ago.
Fiorentina, however, had home advantage in the opening leg in the 2015-16 rematch and their hopes of winning the tie were boosted by the absence of the injured Hugo Lloris from Tottenham's goal.
Yet replacement goalkeeper Michel Vorm was barely tested in a cagey first half that only came to life in the closing stages.
Mauro Zarate fired a loose ball wide with his left foot after 32 minutes as Tottenham's defence had failed to initially deal with a right-wing cross from Josip Ilicic.
The miss from the former West Ham forward proved costly, as the visitors broke the deadlock five minutes later.
Left-back Davies' slalom run into the area was halted by Nenad Tomovic, with Chadli sending Ciprian Tatarusanu the wrong way with his penalty. In converting from 12 yards out, the Belgium international became the first player from an English team to score at Fiorentina's home ground in UEFA competition.
Tottenham looked to have doubled their advantage within two minutes of the second half getting under way, only for an offside decision to rule out Son Heung-min's stooping header from a Christian Eriksen free-kick.
Chadli was then denied by a smart low save by Tatarusanu before Fiorentina equalised with the aid of a rather large slice of luck just before the hour.
Bernardeschi tried his luck from outside the area and hit the jackpot, as his left-footed drive clipped Mason's attempted block and looped over Vorm via a deflection off the underside of the crossbar.
Fiorentina should have gone on to claim the lead in the closing minutes, yet Gonzalo Rodriguez failed to get enough contact with a near-post header from a corner when ideally placed to nod home.