Two sides who advanced from this round will playing group phase football for the very first time. One of them are Albania's Egnatia, who beat Shamrock Rovers 5-1 in Rrogozhine and 6-4 on aggregate.
Having fallen 3-1 last week, the hosts had their work cut out for them to turn things around. Yet, it took them less than five minutes to halve their deficit. Daniel Adjessa's first of two on the night gave his team hope.
By the midway mark of the opening period, Egnatia were ahead on aggregate, as Alessandro Albanese and Ildi Gruda chipped in to send the home fans into delirium.
Shamrock, who won all three previous clashes with Albanian opposition, had just one shot in a first half dominated by the home team.
A red card on the stroke of half-time gave the League of Ireland pacesetters hope, only for Egnatia to add a fifth by the hour mark via Albanese.
Graham Burke's consolation goal with 16 minutes left did not change the outcome as the Hoops suffered back-to-back European eliminations in the same seasons for the first time.
Egnatia will be Albania's second-ever participants after Skenderbeu Korce reached the Europa League proper in 2015/16 and 2017/18.
Iberia 1999 also secured a league phase spot for the first time after a 2-1 extra time success against Larne of Northern Ireland in Tuesday's only match.
Nika Sikharulashvili was the hero for the Georgians, who now join Dinamo Tbilisi as the only sides from the country to play group stage football. Dinamo did so 22 years ago in the UEL's predecessor, the UEFA Cup.
Also in the domestic champions path, Thun held off Vikingur Reykjavik 5-3 over the two legs despite losing 3-2 in the Icelandic capital.
Vikingur, who made the knockout rounds of the UEFA Conference League in 2024/25, came from behind twice at home, before finally cutting the deficit down to two with 35 minutes left. Unfortunately for them, they could not turn things around.
CS Universitatea Craiova came from a goal down to beat KuPS Kuopio 2-1 and advance 3-2 overall. Carlos Mora bagged the winner shortly after the hour to send the Romanians through. Omonia Nicosia edged Lincoln Red Imps 1-0 in their match to beat the Gibraltarian outfit 2-1 on aggregate.
Lech Poznan will face KI Klaksvik on Friday due to the Polish club arriving to the Faroe Islands much later than planned. Averse weather forced them to stay in Norway until it was safe to complete the trip. KI are 1-0 down from the first leg.
Anderlecht, Besiktas prevail in both legs
The only two teams to win both legs of their UEL third qualifying round ties were Anderlecht and Besiktas, though Lech could join them.
After missing out on league phase football last term, former UEFA Cup winners Anderlecht got the better of nine-man PAOK 3-2 at home, completing a 4-2 aggregate success.
Taking a two-goal lead on the night shortly after the restart, the Brussels-based side were able to hold on despite conceding a penalty near the end. They are now unbeaten in their last six qualifying round home matches (5-1-0).
As for Besiktas, they finished off Hradec Kralove, winning 1-0 for the second week in a row. Vaclav Cerny's first half goal did the trick for the Turks, two-time quarter-finalists in the competition.
Hradec lost both legs of a two-legged tie for the very first time, with this being just their third European campaign and first since 1995/96.
Elsewhere, Rangers were unable to overcome their first leg reverse against Jagiellonia Bialystok. Lawrence Shankland's penalty was cancelled by a Nic Prelec goal midway through the second half as the Polish outfit won 3-2 on aggregate following their 1-1 draw at Ibrox.
The other Scottish club in the round, Hearts, drew their game 1-1 as well. However, having been soundly beaten by Benfica 6-1 last week, the stalemate at home was a mere consolation.
In Cyprus, RB Salzburg held off a spirited Pafos team in a back-and-forth contest. The hosts took a two-goal advantage in the first half to hold the aggregate lead at the break.
There was no panic from the Austrians though, with Haris Tabakovic netting a 16-minute hat-trick in the second half to send them through. It ended 3-3 on the night, and 4-3 across the two legs.
Ferencvaros were given a test against Gornik Zabrze, with an own goal eight minutes from time propelling the Hungarians to a 1-1 result in Poland to move on 2-1 on aggregate.
CSKA Sofia will enjoy group phase football for the first time in five years despite losing 3-1 at home to Maccabi Tel Aviv. The Bulgarians, who won 3-0 in their away leg last week, moved on 4-3 over the two legs.
The playoff round will feature 24 teams in total, including the 13 winning sides in this round. Joining them there are five automatic entrants plus the six losing teams from the Champions League third qualifying round, domestic champions path.
Follow everything going on in the UEFA Europa League qualifiers on Flashscore.