With both teams hanging on to a top-eight place prior to kick-off, a win for either would secure their place in the last 16 while effectively consigning the loser to the play-off round.
As such, it was perhaps no surprise to see a first half with several chances at either end.
The first, around 10 minutes in, required a crucial block from Samsunspor’s Logi Tómasson to deny Nadiem Amiri, before the Germany international swung a free-kick narrowly past the post near the quarter-hour mark.
Only a slice of fortune then stopped Mainz from going behind midway through the half. Daniel Batz did fantastically to thwart Emre Kılınç, but the ball rebounded to Carlo Holse for what seemed like an easy finish. However, his goal-bound shot was kept out by his own teammate Kılınç.
Amiri later had a shot well-saved by Okan Kocuk before Mainz broke the deadlock on the brink of half-time through Silvan Widmer, who stroked into the corner from inside the area to give the home side a timely boost.
Within two minutes of the restart, Mainz extended their advantage. Jae-sung Lee’s attempt at hooking a ball back into the box was handled by Rick van Drongelen, convincing referee Mohammad Al-Emara to point to the penalty spot.
From there, Amiri made no mistake, firing into the corner despite Kocuk diving the right way to end a seven-game goal drought. That took the sting out of the match, with Mainz happy to sit back as Samsunspor struggled to create clear-cut openings.
Ultimately, the second half was very different to the first as it lacked the same intensity, allowing Mainz to see out the game with relative ease.
As such, they progress to the knockout stages of a UEFA competition for the first time in their history as Fischer continues to build momentum at the MEWA Arena. Samsunspor, meanwhile, will have to make do with a play-off tie, with this their seventh consecutive game without a win in all competitions.
Flashscore Man of the Match: Nadiem Amiri (Mainz)