Chelsea reached the quarter-finals of the Champions League for the first time in seven years with a 3-0 aggregate win over Atletico Madrid.
Until then their dominance in possession had not translated into chances in front of goal, and in a nervy opening they also appeared fortunate to survive a penalty appeal after visiting winger Yannick Carrasco was pulled back by Blues captain Cesar Azpilicueta.
Italian official Daniele Orsato waved away the claim, and the incident was not examined by VAR.
Atletico knocked Liverpool out of the competition in dramatic fashion at the same stage last term, but the La Liga leaders rarely looked capable of recovering after Ziyech's goal.