Derry put in valiant performance but were defeated 1-2 in the home tie.
That Benfica squad included the likes of Aldair, Valdo, Mats Magnusson and Jonas Thern. They went on to reach the final of the competition that season.
The Lisbon giants were defeated 1-0 by an incredible AC Milan team that has been put forward as a candidate for the greatest club side of all time.
Here is a selection of photographs of the occasion from September 1989.
. Alex Krstić
Alex Krstić Photo: archive
. Stuart Gauld and Mats Magnusson challenge in the air.
Stuart Gauld and Mats Magnusson challenge in the air. Photo: archive
. Benfica and Portugal legend Eusébio was among the visitors to the Brandywell in September 1989.
Benfica and Portugal legend Eusébio was among the visitors to the Brandywell in September 1989. Photo: archive
1. Stuart Gauld and Mats Magnusson challenge in the air.
Stuart Gauld and Mats Magnusson challenge in the air. Photo: archive
2. Benfica and Portugal legend Eusébio was among the visitors to the Brandywell in September 1989.
Benfica and Portugal legend Eusébio was among the visitors to the Brandywell in September 1989. Photo: archive
3. The teams take the field in the first round of the European Cup in 1989.
The teams take the field in the first round of the European Cup in 1989. Photo: Archive
4. Tim Dalton gathers the ball to the relief of Paul Curran and Kevin Brady.
Tim Dalton gathers the ball to the relief of Paul Curran and Kevin Brady. Photo: archive