Manchester City and Arsenal have paid a heavy price for their failure to win their Champions League group stages.
Manuel Pellegrini's punishment for falling short is a clash with Barcelona.
Arsene Wenger will face champions Bayern Munich.
What a difference one more point might have made.
Bayern continued their domestic domination at the weekend, thumping Hamburg 3-1 at the Allianz Arena and opening up a seven-point lead over Bayer Leverkusen and a 12-point lead over third-placed Borussia Dortmund.
Pep Guardiola has achieved what few thought possible in the summer - he has somehow found a way to improve the best team in Europe.
Arsenal have improved too, of course, and still sit at the top of the Premier League despite that heavy defeat by City last Saturday. But the Gunners will be underdogs in this clash.
Barcelona were victorious at the weekend too, overturning Villarreal at the Nou Camp.
They are five points ahead of third-placed Real Madrid, but lead Atletico Madrid only on goal difference.
Gerardo Martino has had less joy with Guardiola's old side and has come in for criticism for the way his team have performed, but they remain one of the best teams on the continent.
And they still have Lionel Messi.
City will have to be at their best.
Of course, if you're going to win the Champions League, you have to face the big teams sooner or later.
But Wenger and Pellegrini will look at Manchester United's tie with Olympiakos with envious eyes.
The Greek side were beaten home and away by PSG and qualified only by virtue of a superior head-to-head record with third-placed Benfica.
They are worthy of respect, of course, but there is no question that they were certainly the team that everyone wanted to face.
Over at Stamford Bridge, Jose Mourinho had been telling anyone who would listen that he wanted Galatasaray in the next round, because it would give his former striker Didier Drogba a chance to return to west London and take in the adulation of his fans.
He didn't add that the Turkish side are also one of the weaker sides in the final stages and would make for eminently beatable opposition.
Elsewhere, the most intriguing tie is AC Milan, wracked by instability and inconsistency, against the surprise package of Atletico Madrid. Diego Simone has, with resources that are dwarfed by Barcelona and Real Madrid, built an excellent attacking side and they would be a match for any of Europe's superpowers.
Diego Costa, despite having a temperament that makes Luis Suarez look like a choir boy, is a phenomenal source of goals, and in young midfielder Koke, they have one of Europe's hottest talents.
City rivals Real Madrid have landed Schalke.
While there are few teams in Europe with the natural resources of the German side, there are also fewer who have so consistently fallen below expectations.
Schalke have some excellent young players, notably the superb Julian Draxler, but they are unlikely to present too much of a problem for Carlo Ancelotti's men, even though they are not at their best.
Ancelotti's old team, Paris St Germain, will also be confident of progression against a Bayer Leverkusen team that shipped nine goals to misfiring United in the group stages.
The Russian Football League's decision to move their season in line with the rest of Europe to prevent their teams from entering the latter stages "cold" could be vindicated in the next round.
League leaders Zenit St Petersburg will face an injury-ravaged Borussia Dortmund. The shock of the round could come there.
As for the biggest games of the round, they belong to Arsenal and Man City.
Not for the first time, the importance of finishing first in the group stages has been stressed.
Man City beat Bayern Munich 3-2 in their final Group D game but could have topped the group had they won 4-2. Arsenal lost 2-0 to Napoli when a draw would have given them top spot in Group F.
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