At least they should try to defend their first position because it is very difficult to maintain the best position because there will be many opponents who will try to knock them down.
One of them is Dortmund, and both will face each other on Alte stadium Berlin next week, so if Union doesn't have trouble and can win easily will determine their next step. Union is beyond expectation for this session, many observers said this season is the same as last year with the same club, Bayern, Dortmund, and Leipzig, but Union appears at the top of the rank. with this hype, Union will make a surprise win with 2 different goals next week.
Although Union Berlin has performed better this season, it is not an easy thing to beat Dortmund even though Union Berlin is playing as the host.
So far, Union Berlin have only lost once away from home to Frankfurt. today Union Berlin will be busy with the Europa league match against Malmo, two days later Union Berlin will host Dortmund. quite a tiring match I think for them.
from the H2H statistics of the matches between their meetings, Union Berlin was beaten three games by Dortmund with a fairly large score. next week, it looks like Union Berlin will be in trouble to beat Dortmund even though they play as hosts.
In my estimation, Dortmund will win this match.