After seven rounds, the German import is emerging as one of the finest attacking midfielders to play in the competition.
And that's no mean feat considering the influence exerted on the league by such gifted foreign stars as Carlos Hernandez, Marcos Flores, Thomas Broich, Gui Finkler and Milos Ninkovic.
Baumjohann was in sparkling form in the Friday night clash with Central Coast Mariners at Spotless Stadium, which the home side won 2-0.
He stole the show with a few numbers of high quality that drew gasps of disbelief from television commentators.
His distribution with surgical precision was a delight to watch, particularly an outrageous, no-look, back heel pass to Jaushua Sotirio in the second half that deserved to be rewarded with a goal.
We will not see a better pass this season unless Baumjohann himself raises the bar even further with another sample of his exquisite skill, peripheral vision and inspired spontaneity.
He also played a role in the Wanderers' two goals, first by keeping the ball alive and opening up play on the left that led to the stunning strike from Keanu Baccus and then by playing another cheeky back heel pass that came to Bruce Kamau, whose shot was parried by goalkeeper Ben Kennedy and Sotirio was first to the rebound to steer the ball home.
The German master, who will be 32 in January, is in his first season in Australia and could well become as influential for the Wanderers as club legend Shinji Ono, particularly if his one-year deal is extended.
And if Sydney FC have any aspirations to extend their run of positive results against their crosstown rivals in Saturday's derby at ANZ Stadium, they would be well advised not to let Baumjohann dictate matters in midfield because the way he's playing he could well be the difference between the two teams.
Baumjohann and his teammates were overwhelmed by the Sky Blues when the two teams last met at the Sydney Cricket Ground in round two.
Goals from Adam Le Fondre and Alex Brosque gave Sydney a comfortable victory.
But this time things might not be that easy for the Sky Blues, essentially because Baumjohann is not any more the foreign import playing alongside new players in a new league.
He is now more familiar with our pitches and weather and is running the show for Markus Babbel's team with all the skill and experience gained by learning the trade at such famous German clubs as Schalke 04, Borussia Monchengladbach, Kaiserslautern, Hertha Berlin and Bayern.
Baumjohann is such a clever and effective playmaker that you suspect that the A-League would have seen more of his special gifts if he played with a more consistent team than the Wanderers.
They are hard to judge, the Wanderers. They generally have been rather poor this season but in patches they have produced some excellent football.
Can you imagine what impact Baumjohann could have had on the competition if he were on the books of, say, Perth Glory, Melbourne Victory, Sydney FC or Adelaide United ... four teams that are replete with seasoned campaigners and quality forwards ready to feast on his silver service?
You suspect that a few of the Wanderers' personnel might not be on his wavelength ... same as some Sydney FC players were too slow to read Alessandro del Piero when the Italian graced us with his presence from 2012 to 2014.
And those who are - like misfiring striker Oriol Riera - lack the quality to finish off what he initiates.
Next Saturday's intra-city clash is shaping as a close contest between a team that believes it is stronger and should win against another that is showing signs of a revival and feels it's about time to win a derby.
It would be interesting to see if the methodical Baumjohann, who operates with Teutonic efficiency, can steal the show from the explosive Ninkovic, who can win a game on his own with a moment of magic.
It should be the battle within the battle, an indirect confrontation featuring the finer and more artistic side of the game that should satisfy the most discerning of football followers.
