The 25-year-old, who will take over top spot from Poland's Iga Swiatek with victory at the Paris Grand Slam, did not have an easy start with qualifier Shymanovich, ranked 214th, matching her power with every groundstroke.
Shymanovich started moving her opponent around, playing the angles and forcing her to the net with audacious drop shots as she tried to stop Sabalenka imposing her own rhythm on the match.
The second seed wasted two set points at 6-5 but bagged the set on her third opportunity, chasing down yet another drop shot from her opponent.
She took a two-game lead at the start of the second set but had to fight tooth and nail for every single point before sealing victory on her second match point.
Reporting by Karolos Grohmann, editing by Ed OsmondOur Standards: The Thomson Reuters Trust Principles.
Persons:
Roland Garros, Iryna Shymanovich, Benoit Tessier PARIS, Sabalenka, Shymanovich, Karolos Grohmann, Ed Osmond
Organizations:
Belarus, Iryna Shymanovich REUTERS, Shymanovich, Paris, Thomson
Locations:
Paris, France, Belarus