Benfica beat Madrid 4-2 after the most amazing finish in the final round of group matches on Wednesday to deny the 15-time European champions direct qualification to the round-of-16 and force them into the uncertainty of the playoffs.
Benfica sealed their place in playoffs only when their Ukrainian goalkeeper Anatoliy Trubin popped up in the eighth minute of added time to head home their fourth. It prompted delirious scenes on the touchline with Mourinho at the centre of the celebrations.
Defeat meant Madrid, who had started the match in third place, dropped out of the top-eight, who directly advance to the round-of-16.
Mourinho, a two-time Champions League winner with Porto and Inter Milan, will have the chance to inflict more pain on his former club, who let go of coach Xabi Alonso last month and have turned to Alvaro Arbeloa to try to salvage the season.
Defending champions Paris Saint-Germain must also take the playoff route and face an all-French showdown with Monaco.
This season's surprise package, tiny Norwegian team Bodo/Glimt, will play last year's beaten finalist Inter Milan.
The winners of the two-legged playoffs will advance to the round-of-16, where Madrid may yet face another showdown with Manchester City.
In the Europa League playoffs draw, Nottingham Forest will play Turkish side Fenerbahce, Scottish champions Celtic take on Germany's Stuttgart, while Spanish club Celta Vigo will be up against Greek team PAOK.
CHAMPIONS LEAGUE PLAYOFF DRAW (first legs to be played over February 17-18, second legs February 24-25).
Benfica vs. Real Madrid, Bodo/Glimt vs. Inter Milan, Monaco vs. Paris Saint-Germain, Qarabag vs. Newcastle, Galatasaray vs. Juventus, Brugge vs. Atletico Madrid, Borussia Dortmund vs. Atalanta, Olympiakos vs. Bayer Leverkusen.
Teams qualified automatically to the round of 16: Arsenal, Bayern Munich, Liverpool, Tottenham, Barcelona, Chelsea, Sporting Lisbon, Manchester City.
