They were about to lock horns in the UEFA Champions League quarter-finals while each looked well placed to emerge as champions of their own domestic leagues. Leverkusen also had their sights on the German Cup, while Liverpool were following up a UEFA Cup, FA Cup and League Cup hat-trick from 2000/01.
Indeed, their last-eight meeting was a classic, Leverkusen winning through following an exhilarating second leg that finished 4-2 at the BayArena, the English side having prevailed 1-0 at Anfield. But for both teams it proved the prelude to serious disappointments.
Leverkusen edged out Manchester United FC on away goals in the semi-finals but their treble dream was shattered when in quick succession they conceded the Bundesliga title to BV Borussia Dortmund on the last day of the league season, lost the German Cup final to FC Schalke 04 and then were unable to find an answer to Zinedine Zidane's stunning strike for Real Madrid CF at Hampden Park. Meanwhile Liverpool, in the Premiership's pole position at the start of April, were blown away by a spectacular run from Arsenal FC.
That dip in fortunes has continued since, with Liverpool's 2003 League Cup triumph the only trophy either has managed, Leverkusen even fighting relegation the year after reaching the final. So as they prepare to renew rivalry in the Champions League first knockout round they share a wish that victory could herald the start of a more productive future.
There have been many changes in both camps since that 2002 encounter - including the coaches. Klaus Toppmöller survived only nine months at Leverkusen after the Madrid defeat with the team in relegation danger while legendary managing director Reiner Calmund, the club's heart and soul for 27 years, stood down at the end of 2003/04.
At Liverpool, Gérard Houllier struggled valiantly to recapture their success of 2001 but kept coming up short in the championship race. Last summer the Anfield board decided to make a change with Rafael Benítez, fresh from a Spanish league and UEFA Cup double with Valencia CF, installed as manager.
Four of the five marksmen whose goals in that second leg three years ago made for a nerve-shredding spectacle with the advantage lurching first one way then the other, have moved on to pastures new - with Michael Ballack and Lucio departed from Leverkusen and Abel Xavier and Jari Litmanen no longer with Liverpool.
Only Dimitar Berbatov of those goalscorers will line up for Leverkusen, who will be relieved that Fernando Morientes, part of the Madrid side that ended their hopes in the 2002 final, is not eligible to play having appeared for his former club before joining Liverpool in January.
Also remaining with Leverkusen are Jörg Butt, Jens Nowotny, Carsten Ramelow, Bernd Schneider and Diego Placente, while first-leg goalscorer Sami Hyypiä, Jerzy Dudek, John Arne Riise, Didier Hamann, Steven Gerrard and Jamie Carragher are still at Liverpool.
Footballers have to move on, continually looking forward rather than back - the fast-moving nature of today's game demands it. But as they prepare to meet again at Anfield on 22 February, it will be hard for these 12 survivors not to cast a thought back to the drama of three years ago.
©UEFA.com 1998-2015. All rights reserved.