Rangers' Europa League opponents have now gone a full year without losing a single league game as boss Jindrich Trpisovsky hailed their form.
The Czech side face Rangers in a shootout to reach the last eight of the Europa League later this month.
Slavia came from behind twice to beat Synot 3-2 at the weekend to soar 11 points clear of city rivals Sparta Prague, who crushed Celtic 4-1 home and away in the Europa League this season.
That marked a year since they last lost in the Czech League, to the same opponents they beat at the weekend and Trpisovsky insisted it was an impressive achievement.
He said: "We have come a very long way since our last defeat in the league and the players deserve all the praise going.
"We have won the title, played extremely well in the Europa League and are currently first in the table again.
"I'm finding it very hard to even think of any negative things during that time.
"I only made two changes from the team that won at Leicester City and that's a measure of the respect I show to the league competition.
"But this incredible run is all down to the players in my squad and we hope to continue what has been a wonderful season."
