From the ETF2L site
2.2 GROUP PHASE
2.3.1 Playoff Fixture System
After all teams have played their Group matches, the 1st place teams of each group will get promoted to the playoffs in a straight knockout competition with Single Elimination Mode. Every round will be a Best of 3 Maps, which means the first team reaching two Map Wins gets to the next Round.
2.3.2 Maps can not end in a tie: Decider round in case of a draw (5CP/CTF maps)
If the score is tied on a 5CP or CTF map after the timelimit has been reached, a decider round will have to be played. If no team has won a round after 10 minutes have passed the team that is holding the middle point after the 10 minutes will win.