Spurs dominated the first-half chances but went into the break all square, and it was the home side who were by far the better team in the second period as they had 12 shots compared to their opponents' tally of zero.
In the end Mauricio Pochettino would have been happy enough with the point - Leverkusen's fifth draw in succession in the competition - which leaves his side third in the standings, one point off AS Monaco who earned a late draw against CSKA Moscow elsewhere this evening.
High pressing was always going to be a big theme in the game, and it was the hosts who first forced their opponents into a mistake high up the pitch when Danny Rose was dispossessed, but the subsequent cross was well off the mark and the chance went begging.
Vincent Janssen thought he had his first goal from open play in a Tottenham shirt nine minutes in when converting from a Son Heung-min pass, though the South Korean was rightly adjudged to have been offside and the strike was ruled out before celebrations could begin.
Alli, who had scored in each of the Lilywhites' last two games prior to tonight, perhaps should have been doing better from eight yards out as he sent his attempt wide of the target under little pressure.
Home defender Omer Toprak was called into action a couple of times to produce some vital blocks on the edge of the box, but he came close to opening the scoring up the other end when glancing a header wide 32 minutes in.
Spurs dominated the final 10 minutes of the first half, taking control of things and creating two more big chances - Janssen seeing his close-range header come back off the bar, before Erik Lamela's follow-up attempt was somehow kept out by Bernd Leno.
Former Manchester United striker Javier Hernandez, with five goals to his name in the Bundesliga this term - half of his side's total tally - has never previously registered against Tottenham Hotspur, and his frustrations continued as he flashed one wide on the brink of the interval.
Spurs have now shipped just six goals in their opening 12 games of the season but, having made three changes at the back this evening, they were struggling to keep that impressive record fully intact as the match wore on.
Hernandez should have edged his side ahead when given the chance to tap the ball home at the back post, yet he gave Hugo Lloris a glimmer of hope of getting there - and get there he did, despite Hernandez's claims that the ball has crossed the line.
Bayer were starting to make their opponents work far harder as the hour mark approached, with Charles Aranguiz sending in a free kick towards the bottom corner for Lloris to push aside.
From the corner kick, Rose was twice in the right place at the right time to block aside shots that looked destined for the back of the net, and Admir Mehmedi was the next to test Lloris 62 minutes in with another top save down to his right.
Spurs were having to hold on at times in the second half, seeing one penalty call go their way when the ball popped up and hit Rose on the hand, while Stefan Kiessling and Toprak were also denied in quick succession by the visitors' inspired skipper.
Pochettino had to turn to his bench to introduce some midfield reinforcements, bringing on Moussa Sissoko and Mousa Dembele to join Victor Wanyama for the final 20 minutes, but it did not have the desired immediate impact as Toprak again came close to finding a way through.
It was a case of holding on for the visitors, as they were made to settle for the odd counter-attacking move, but in the end there was to be no winner as the German outfit extended their unbeaten run in European competition to nine games.