It was a rough day for Kosta Diamantis.

Federal prosecutors grilled the former state school construction director for hours on Friday during his bribery and extortion trial in Bridgeport.

The questioning got so intense that Judge Stefan Underhill urged everyone to “take the temperature down” before things turned into “a street fight.”

Diamantis was all smiles outside of court.

"I'm happy," he told reporters on his way to lunch.

But inside, Diamantis faced bruising questions over nearly $100,000 in payments he accepted from two construction companies, Acranom Masonry and Construction Advocacy Professionals (CAP).

“The way you [cleaned up school construction] was by taking envelopes of cash from Acranom?” asked Assistant U.S. Attorney Jonathan Francis.

Diamantis replied: “Outside of school construction.”

Acranom officials already testified that they bribed Diamantis – once in a restaurant bathroom – to snag two multi-million dollar jobs and settle a $300,000 payment dispute with Hartford leaders.

"Without Kosta’s involvement or influence, we probably wouldn’t have got that job,” former Acranom vice president John Duffy told jurors last week.

Diamantis insisted that the payments were simply referral “fees” to broker a relationship between Acranom and D’Amato Construction, a general contractor.

The ex-school construction chief said he believed the arrangement was legal. But on the witness stand, Diamantis admitted that he did not report the payments on his taxes or state disclosure forms.

Diamantis said he would be amending his tax returns.

“You got caught and now you think you need to amend them,” Francis shot back.

Diamantis own words turned out to be his worst enemy.

On the witness stand, the former budget deputy insisted that he never traded cash for construction contracts – but he struggled to explain hundreds of texts suggesting otherwise.

“Doesn’t matter end of day you gone [sic] add 70,” one message read.

Prosecutors asked if the real arrangement was for Acranom to “pad the contract and kick the extra 70,000 [dollars] back to you.”

Diamantis replied: “I didn’t expect them to do that.”

One answer left Francis so stunned that he threw his hands in the air.

When questioned about a text saying, “I need 5k desperately tomorrow ... I shouldn’t have to beg. He owes me 77 2 months ago,” Diamantis claimed he was talking about a $77 lunch – not a $77,000 bribe, as Duffy testified.

The former school construction chief contradicted his own testimony several times.

Diamantis testified that he had no say in hiring subcontractors.

But just moments later, he admitted threatening to get Acranom tossed off a project after being shown a text message saying, “I will wait til [sic] Monday for him to give me 40. Or I think Tolland needs a new mason."

Prosecutors also drilled down on CAP owner Antonietta Roy, who said she paid Diamantis’ daughter $45 an hour – despite having no experience in the construction industry – because he asked Roy to "take care of my daughter."

Diamantis insisted he had no role in that either, but prosecutors introduced a series of texts to Anastasia Diamantis that directly contradicted him.

Later, Diamantis wrote that he "negotiated" a $1,500 bonus for his daughter.

Diamantis told jurors the texts were “all tongue-in-cheek." His daughter has not been charged.

Diamantis also claimed that several checks Roy wrote him were legal fees, but admitted that he had no retainer agreement or billing statements to prove it.

The cross-examination got so heated that defense attorney Norm Pattis asked for a mistrial. Afterward, Pattis acknowledged that "I have my work cut out for me."

"Do I think that when he got off the stand, the Hallelujah chorus was singing in support of him? No.," Pattis told reporters.

Closing arguments are expected by Monday afternoon after several architects take the stand.

Former Hartford mayor, and current congressional candidate, Luke Bronin will not have to testify. The defense already dropped a bid to force Gov. Ned Lamont to testify.

Pattis suggested that he doesn’t think prosecutors proved all 21 counts of bribery, extortion, conspiracy and making false statements to the FBI.

“I have an argument that the evidence supports and I’m looking forward to making it” he told reporters. “And if an honest jury listens, I am optimistic about some of the counts.”

For his part, Diamantis said he’s not worried about the text messages.

“Those are things that we already discussed,” he said.