I knew there were no draws in the knockout stage; however, I wasn't sure how the ties are broken. In case you didn't know either....
If the score is tied at the end of regulation, the teams play 30 minutes of extra time. (The 30 minutes are guaranteed; there is no longer any “sudden death” or Golden Goal rule.) If the score is still tied, the game goes to a penalty shootout. (Some soccer statisticians consider games that go to penalties to be draws for record-keeping purposes — but the winner of the shootout advances all the same.)
Shootout:
*The team to take the first kick is decided by a coin toss and the referee chooses the goal at which the kicks are taken.
*All kicks are taken at one goal to ensure that both teams' kick-takers and goalkeepers face the same pitch irregularities (if any), wind and sun conditions, etc.
*Each kick is taken in the general manner of a penalty kick. Each kick is taken from the penalty mark, which is 12 yards out from the goalmouth, with the goal defended only by the opposing goalkeeper.
*Teams take turns to kick from the penalty mark in attempt to put the ball into the net, until each has taken five kicks. However, if one side has scored more successful kicks than the other could possibly reach with all of its remaining kicks, the shoot-out ends regardless of the number of kicks remaining.
*If at the end of these five rounds of kicks the teams have scored an equal number of successful kicks, sudden death rounds of one kick each are used until one side scores and the other does not.