The visitors did not make the return to the top flight they desired last weekend, while hosts Union also were not overly convincing.
Match preview
New Union Berlin manager Bo Svensson faced his former club Mainz on the opening weekend, where he had a fine spell in the early 2020s, and led his side to a 1-1 draw.
It was another new face at the club that scored the equaliser, as Laszlo Benes scored from a Tim Skarke assist just two minutes after the pair had come off the bench in an inspired double switch from the new boss.
That gives Union the opportunity here to remain unbeaten in the opening two games of a Bundesliga season for the fourth straight year, however, after two wins to start the campaign last season, they went on to lose nine in a row, going from top to bottom in the space of just over two months.
Union eventually recovered despite another late wobble to finish 15th and secure a sixth straight season as a top-flight club.
St Pauli have proved fruitful opponents for Union Berlin when they have met recently, especially here in Kopenick, as they are unbeaten in the last eight meetings on home soil - winning seven.
Against newly-promoted opposition in general, Union have been strong, as Heidenheim last season are the only one of those clubs to have beaten them in the last 11 attempts, while none have ever won here at Alte Forsterei in the top flight.
After 13 years away from the Bundesliga, St Pauli made a disappointing return, losing 2-0 at home to Heidenheim on Sunday.
Despite having more shots, more possession and a higher xG, St Pauli came away with nothing, proving how unforgiving the top flight is if you do not take your chances.
The St Pauli faithful will know that all too well after their most recent Bundesliga season too, as their 2010-11 campaign ended dismally, with just one point from 11 games to finish the season, which unsurprisingly led to their relegation.
One good omen they and new manager Alexander Blessin may be clinging onto ahead of this encounter is that the club has never lost their opening two Bundesliga matches, but it will be a test in the capital.
Union Berlin Bundesliga form:
Union Berlin form (all competitions):
St Pauli Bundesliga form:
L
St Pauli form (all competitions):
Team News
Union Berlin could be without defensive pairing Josip Juranovic and Kevin Vogt due to injury ahead of this clash, as the latter went off with a knock late on last week.
Highly-rated young wing-back Tom Rothe, who arrived from Borussia Dortmund over the summer, is yet to make his debut for the club, but may be given an opportunity if injuries continue to mount.
Further forward, Kevin Volland is out with a knee injury, so Jordan Siebatcheu and Benedict Hollderbach should start again in attack, while Benes may come into the side after his impact off the bench against Mainz.
Despite the change in manager, St Pauli have stuck with most of the squad that Fabian Hurzeler got promoted with.
Morgan Guilavogui is the only notable addition to the ranks after his arrival on loan from Lens, and he started against Heidenheim on Sunday, but he will be in competition for a start with Oladapo Afolayan.
On the injury front, the visitors are set to be without Simon Zoller (thigh), Sascha Burchert (muscle) and Soren Ahlers (ankle) for this trip to the capital.
Union Berlin possible starting lineup:
Ronnow; Doekhi, Querfeld, Diogo Leite; Trimmel, Khedira, Benes, Schafer, Gosens; Siebatcheu, Hollerbech
St Pauli possible starting lineup:
Vasilj; Wahl, Smith, Mets; Saliakas, Irvine, Wagner, Metcalfe, Ritzka; Eggestein, Guilavogui
We say: Union Berlin 2-1 St Pauli
Union did well to come back from a goal down and salvage a point on the road last weekend, and the introduction of new signing Benes could be a big factor in deciding this game.