The knockout phase involved the sixteen teams who finished in the top two in each of their groups in the group stage.[4]
Each tie in the knockout phase, apart from the final, was played over two legs, with each team playing one leg at home. The team that had the higher aggregate score over the two legs progressed to the next round. In the event that aggregate scores finished level, the away goals rule was applied, i.e. the team that scored more goals away from home over the two legs progressed. If away goals were also equal, then thirty minutes of extra time were played, divided into two fifteen-minutes halves. The away goals rule was again applied after extra time, i.e. if there were goals scored during extra time and the aggregate score was still level, the visiting team qualified by virtue of more away goals scored. If no goals were scored during extra time, the tie was decided by a penalty shoot-out. In the final, the tie was played as a single match. If scores were level at the end of normal time in the final, extra time was played, followed by penalties if scores remained tied.
The draw mechanisms for the knockout stage is as follows:
In the draw for the round of 16, the eight group winners were seeded, and the eight group runners-up were unseeded. A seeded team was drawn against an unseeded team, with the seeded team hosting the second leg. Teams from the same group or the same association cannot be drawn against each other.
In the draws for the quarter-finals onwards, there were no seedings, and teams from the same group or the same association could be drawn with each other.
The draw for the round of 16 was held on 16 December 2011.[5] The first legs were played on 14, 15, 21 and 22 February, and the second legs were played on 6, 7, 13 and 14 March 2012.
The draw for the quarter-finals was held on 16 March 2012.[22] The first legs were played on 27 and 28 March, and the second legs were played on 3 and 4 April 2012.
The draw for the semi-finals was held on 16 March 2012, after the quarter-final draw.[22] The first legs were played on 17 and 18 April, and the second legs were played on 24 and 25 April 2012.
The final was played on 19 May 2012 at the Allianz Arena in Munich, Germany. A draw was held on 16 March 2012, after the quarter-final and semi-final draws, to determine the "home" team for administrative purposes.[22]
Note: In 1991–92, the competition was still known as the European Cup, but is included as it was the first to use a group stage format. In that season and 1992–93, there was no knockout phase between the group stage and final.
