Spurs finished second to Bayern Munich in Group B to reach the knockout stages for a third season running, while Leipzig topped Group G to reach this stage for the first time.
The performances may not have been all that convincing, but Tottenham have racked up three wins on the spin and gone seven matches without defeat in all competitions.
Jose Mourinho was brought in to transform Spurs' fortunes, and slowly but surely he is achieving that.
The gap on the Premier League's top four now stands at one point ahead of Chelsea's clash with Manchester United on Monday, while a home meeting with Norwich City awaits in the last 16 of the FA Cup early next month.
Throw this Champions League showdown with Leipzig into the mix and there is plenty for Tottenham to play for in the coming weeks, meaning that they have hit their best form of the campaign at just the right time.
The Lilywhites conceded 14 goals in their six group-stage matches - the highest tally among the remaining teams in the competition - with half of those goals coming in the 7-2 home defeat against Bayern Munich.
Indeed, the Tottenham Hotspur Stadium has seen more goals than any other venue in this season's Champions League (20 goals - 11 for Tottenham and nine against).
Leipzig will likely focus on the counter-attack in Wednesday's clash and they have seemingly found their scoring touch again after putting three goals past Werder Bremen at the weekend.
That 3-0 win brought an end to a four-match winless run in all competitions that had threatened to derail their campaign somewhat.
Leipzig advanced from a Champions League group that also contained Lyon, Benfica and Zenit St Petersburg, losing just one of their six matches.
Into the last 16 for the first time in their history and with the Bundesliga title race wide open, 2019-20 is shaping up to be one to remember for Nagelsmann's side.
Tottenham Hotspur's Champions League form: DLWWWL
Tottenham Hotspur's form (all competitions): DWDWWW
RB Leipzig's Champions League form: WLWWDD
RB Leipzig's form (all competitions): WLDLDW
Tottenham will be without Harry Kane all the way up to the final should they make it that far due to a hamstring injury sustained against Southampton on New Year's Day.
Nagelsmann is expected to stick with a back-three formation, which could potentially see Manchester City loanee Angelino slot in at wing-back.
Tottenham Hotspur possible starting lineup:
Lloris; Aurier, Alderweireld, Sanchez, Davies; Alli, Winks, Lo Celso; Son, Moura, Bergwijn
RB Leipzig possible starting lineup:
Gulacsi; Mukiele, Klostermann, Halstenberg; Sabitzer, Haidara, Laimer, Angelino; Nkunku; Werner, Poulsen
We say: Tottenham Hotspur 2-1 RB Leipzig
Tottenham will be hoping to avoid a repeat of the last occasion a German side visited their ground, with that heavy loss to Bayern still fresh in the memory. In what is the first ever competitive meeting between the sides, we are tipping Spurs to edge a tight contest in North London and take a slender advantage to Germany for the return match next month.