Bologna pushed Sampdoria deeper into Serie A trouble on Sunday as they handed Claudio Ranieri's side a third 2-1 defeat in eight days while Sassuolo were involved in another six-goal thriller, this time drawing 3-3 with Verona.
Barrow then hit the post before Federico Bonazzoli headed one back for Sampdoria with two minutes left.
Orsolini's goal did not appear to impress his coach Sinisa Mihajlovic, however.
"I expected more from him," said Mihajlovic. "If I had a suitable replacement on the bench, I would have changed him at the end of the first half because I didn't like his performance. Then he stayed on the field and scored.
"There was a lot of effort, but that's the minimum," he added. "I expect more from him -- dribbles, passing exchanges, he needs to take some risks."
Sampdoria, who lost by the same scoreline to Inter Milan and then AS Roma, dropped into 17th place with 26 points, only one place and one point above the danger zone. Bologna are 11th.
Halftime substitute Jeremie Boga scored twice and Rogerio snatched an equaliser in the seventh minute of stoppage time as Sassuolo fought back from 3-1 down to draw 3-3 at home to Verona, four days after holding Inter Milan by the same score.
However, Boga curled one in for Sassuolo the 77th minute and Rogerio scored with a shot off the post deep into stoppage time to complete another dramatic fightback for the Neroverdi.