Brennan Johnson's first-half double put the hosts in control but Saints rallied after the break, and deservedly halved the deficit in the 90th-minute through Mateus Fernandes' strike.
There was still time for Johnson to be fouled by Welington in the box, earning a 94th-minute spot-kick, but the Wales winger was denied the chance at a hat-trick, with substitute Mathys Tel converting from the spot instead.
Unfortunate to be ruled marginally offside by the VAR for a disallowed goal by Lucas Bergvall.
Deputised solidly for Micky van de Ven but will surely return to the bench on Thursday.
Made the opening goal for Johnson with a smart overlapping run. Outnumbered at the far post for Fernandes' goal -- a consequence of the tactics rather than his own shortcomings.
Got into some more dangerous positions than usual, including ahead of the second goal.
Unlucky to have a goal ruled out for a tight offside against Romero.
Made the second goal with a header into Johnson's pass. Some of his passing was eye-catching.
Took both of his goals well, potentially giving Ange Postecoglou a selection dilemma for Frankfurt.
Had an effort blocked after a lively counter. Withdrawn before the hour to save his legs.
No chance to make an impact as Spurs sat back.