Seemingly caught off guard by Sondland's testimony - which more sharply alleged that there was a clear effort to condition aid to Ukraine for a series of investigations than his previous deposition testimony - Republicans ultimately took the gloves off, and took after the President's own ambassador.
"You really have no testimony today that ties President Trump to a scheme to withhold aid from Ukraine in exchange for these investigations," said Rep. Mike Turner (R-OH).
"Other than my own presumption," Sondland interjected, further aggravating Turner, his voice growing more strident by the minute.
"Do you know what hearsay evidence is ambassador?" Turner asked. "Do you know what made up testimony is?"
GOP lawmakers mocked Sondland's earlier statement that he presumed the aid-for-investigations effort was true, when he said he realized 'two plus two equals four.'
"Two presumptions plus two presumptions does not equal even one fact," said Rep. Brad Wenstrup (R-OH).
Earlier, GOP counsel Stephen Castor sought to undercut Sondland's testimony, rattling off a series of items which Sondland did not have to back up his presumption.
"You don't have records, you don't have notes, because you didn't take notes, you don't have a lot of recollections," Castor said.
"I mean, this is like the trifecta of unreliability, isn't that true?" Castor asked, who did not gain the agreement of Sondland.
"What I'm trying to do today is use the information I have to be as forthcoming as possible," said Sondland.
Republicans also complained openly to Sondland about why he did not use a quote from the President - which Sondland had used in a text message - denying any kind of quid pro quo.
"Do you know what a quid pro quo is?" asked Rep. Jim Jordan (R-OH), who said Sondland should have made that one of the first items in his lengthy opening statement.
Ironically, at the start of the hearing, the top Republican on the Intelligence Committee, Rep. Devin Nunes (R-CA), warned the Oregon hotel developer that he faced a difficult day.
"Ambassador Sondland, you are going to be smeared," Nunes declared.
But the roughest treatment for Sondland actually came from the GOP, and not from Democrats.