Ms Sturgeon was being questioned by Labour interim leader Alex Rowley about tax rises, but she seized on claims by the Fife MSP that the SNP "sides with the millionaires."
This prompted uproar on the SNP benches as Nationalists MSPs howled in derision and pointed towards Mr Sarwar, after it emerged his family firm does not pay workers the "real" living wage or recognise trade unions.
"Another party for the few not the many," Mr Rowley added to further jeers from Nationalists.
The First Minister seized the opportunity to turn Mr Rowley's comments back on the current Labour leadership contest where Mr Sarwar is up against left-wing candidate Richard Leonard.
"I thought it was unfair of Alex Rowley to personalise this debate by bringing Anas Sarwar into it," Ms Sturgeon joked.
"The problem here, as Anas Sarwar so clearly illustrates, is that there is a massive gulf - a gulf as wide as the Clyde - between what Labour says and what Labour does.
"We have a Labour leadership candidate lecturing others about doing the right thing on pay and yet his own family firm won't pay the living wage voluntarily.
"So Labour should get its own house in order."