The Mercedes driver, who has held a strong position in the title race this season, will start Saturday's race from 16th after hitting the wall during the opening qualifying session in Baku. His teammate and closest championship rival, George Russell, secured pole position with a commanding performance.
Antonelli admitted that he misjudged the grip on his second qualifying lap after being encouraged by his opening effort.
"I misjudged with the grip being so different compared to the first lap. I hit the wall. Unnecessary mistake early on," he said.
The 20-year-old added that the incident was a reminder that he needs to remain focused throughout every session.
"It's a good way to come back to earth and to remind myself I need to be on top of it every time because otherwise I do these mistakes and a very stupid one," Antonelli said.
He also admitted that he was "very mad" with himself following the incident.
Antonelli had already faced difficulties in Baku after losing valuable track time because of a reliability issue during Thursday's practice sessions. His Mercedes developed a hydraulic leak halfway through the opening session, leaving the team unable to send him back onto the circuit until midway through the second session.
Despite those setbacks, Antonelli was only 0.252 seconds behind Russell in final practice. He then briefly looked quicker than his teammate during his opening qualifying run, before his crash ended his session.
The mistake gives Russell an opportunity to reduce the 81-point gap between them in the championship standings. However, Russell emphasized that Antonelli had been almost flawless throughout the season and that this was his first major error during a qualifying or race session.
"You can't discount Kimi. He started 19th in Monza and now he's in 16th," Russell said, referring to Antonelli's victory at the Italian Grand Prix after starting from the back because of a penalty.
Russell secured pole by 0.837 seconds, with Ferrari's Charles Leclerc second and Oscar Piastri third. Max Verstappen qualified eighth after experiencing several problems, including an engine issue that cost him speed on the straights and a battery problem during Q3.
The Baku street circuit is known for its long straight and opportunities for overtaking, meaning Antonelli will have plenty of chances to recover positions when the race begins.
The Azerbaijan Grand Prix is scheduled for Saturday at 12:00 BST.
