Michael D. Cohen, Donald Trump’s former fixer and current antagonist, faced a tough cross-examination on Thursday as the defense drilled into his past lies.

Mr. Cohen, once known as a hothead and a paid bully, did not explode as he did when testifying last fall at Mr. Trump’s civil fraud trial. He seemed at times stressed under the searing questioning from Mr. Trump’s attorney, Todd Blanche. In one dramatic moment, Mr. Blanche accused Mr. Cohen of inventing the content of a phone call just before the 2016 election that he testified was with Mr. Trump and in which they discussed a hush-money payment.

“That was a lie,” Mr. Blanche said, his voice rising.

Mr. Cohen is not done. After more than seven hours of cross-examination over two days, he will return to the stand Monday; the judge granted Mr. Trump a day off on Friday so he can attend his son Barron’s graduation.

The former president is charged with falsifying 34 business records related to the reimbursement of the $130,000 hush-money payment to a porn star, Stormy Daniels, who says she had a sexual encounter with Mr. Trump in Lake Tahoe, Nev., in 2006. Mr. Trump, 77, has denied the charges and having had sex with Ms. Daniels. If convicted, he could face prison or probation.

Here are five takeaways from Mr. Trump’s 18th day, and his fifth week, on trial.

The content of a call could be trouble for Cohen.

It was a startling moment: Mr. Blanche on the attack, accusing Mr. Cohen of lying about a brief phone call on Oct. 24, 2016, which Mr. Cohen had previously said was to update Mr. Trump about the $130,000 he was going to pay to Ms. Daniels. Mr. Blanche, however, suggested Mr. Cohen was instead talking to a Trump bodyguard, Keith Schiller, about being the victim of phone pranks.