The Danish side, having lost 4-1 in their home leg to Lech Poznan, had work to do in the return game. The hosts had a penalty overturned early on, before Tobias Bech put AGF ahead just past the half hour mark.
A Kristian Arnstad penalty after the restart gave the visitors even more hope. Frederik Tingager gave his side the leveller on aggregate, erasing the three-goal deficit.
Lech took the lead back in extra time, only for AGF to respond five minutes later. Just like that, the score on the night was 4-1, just as it was a week prior. In the penalty shootout, the Danes also had to recover there, falling behind after the first round.
However, the next two penalties from Kolejorz failed to find the back of the net, and from there, AGF scored the rest of their to finish off the comeback by winning 4-3 on spot kicks.
The side from Aarhus will be playing in a league phase for the first time in the club's history after turning their tie around. Several of Tuesday's winners will also celebrate the same feat.
Poland's other representatives in Champions League qualifying, Gornik Zabrze, were unable to recover against Fenerbahce in their match. Talisca's penalty very early on gave the Turkish outfit a 2-0 aggregate advantage. While Michal Sacek got one back on the stroke of half time, Fener held on to prevail 2-1 overall despite the 1-1 draw on the night.
One other match needed penalties, as Kairat Almaty managed to beat 10-man Omonia Nicosia 1-0 at home to tie the aggregate score at 1-1. Playing up a man since the 26th minute, the team from Kazakhstan had 37 shots in the 120 minutes of play.
In the shootout, Nikolas Panagiotou's decisive effort failed to go in, sending Kairat through 6-5 after seven rounds. For the second year running, they will play in the third round of UCL qualification.
Of the eight winning teams from Wednesday's matches, the only side to prevail across both legs were Crvena zvezda, who finished off Northern Ireland's Larne 5-0. Just like the first leg, the Serbs were on top from minute one, creating chance after chance. The Invermen were no match for the former European Cup winners, who move on 9-0 over two legs.
Kauno Zalgiris, Be'er Sheva win late on
In other UCL action from Wednesday, Lithuania's Kauno Zalgiris secured European football in the fall after scoring a late winner against KI Klaksvik. Leon Krekovic's strike five minutes before the end was enough for the home side to triumph 1-0 on the night and on aggregate.
Zaliai Balti, who are unbeaten in their four UCL games this summer, are the second team from Lithuania to make the group phase in a UEFA club competition after Zalgiris Vilnius. This was also the second time they managed to keep clean sheets in both legs of a tie, having done so against Europa FC in the Conference League in 2021.
The last time KI were shut out in both matches of a two-legged tie was in 2019 against Luzern.
Hapoel Be'er Sheva were successful in overturning their first leg reverse against Vikingur Reykjavik. Playing their home leg in Hungary, the Israeli club got goals from Zahi Ahmed and Amir Chaim Ganah to complete a 2-0 win and 2-1 aggregate victory.
The result means Be'er Sheva will feature in a group phase for the first time since 2022/23.
Lesvki Sofia were given a scare against CS Universitatea Craiova, going up 2-0 away to seemingly put the tie to bed. The Romanians did not give up though, as goals just before and immediately after the break saw them return the deficit to just one.
Fortunately for Levski, they managed to hold on for the rest of the second half to win the tie 3-2 after the 2-2 draw in Romania. Their last group phase appearance came in the Europa League in 2010/11.
Slovan Bratislava, coached by former Ivorian international Yaya Toure, finished off Iberia 1999 with a 1-1 stalemate. That proved to be enough for the Slovak team, who advanced 3-1 on aggregate.
The third qualifying round will take place on 4/5 August (first legs) and 11 August (second legs). All 20 teams involved in the round are assured league phase football in one of the three club competitions.
Follow all of the UEFA Champions League qualifying round action on Flashscore.