ServiceNow shares sank 25% on Thursday and headed for the worst day ever after the enterprise software company's third-quarter results underwhelmed, reigniting artificial intelligence disruption concerns.

"This was a little bit uncharacteristic for ServiceNow standards, just in terms of the lack of upside," Citi's Tyler Radke told CNBC on Thursday.

Revenue grew more than 20% during the period to $4.11 billion, which was roughly in line with a $4.10 billion estimate from analysts polled by LSEG. Adjusted earnings came up short at $1.00 per share, compared to a forecast of $1.02.

The results did little to overturn recent "SaaSpocalypse" fears, or concerns that new AI capabilities will upend traditional software business models.

The stock drop came even after the company slightly lifted its full-year 2026 subscription revenue outlook to between $15.78 billion and $15.79 billion. Net new AI average contract value jumped 65%.

One factor spooking investors is the lack of immediate payoff for the company's investments in its newly formed forward-deployed engineering team that embeds in enterprises to build AI solutions, Radke said.

"It's just going to be a little bit longer of a waiting game, and so I think the market, you know, wanted to see something a little bit sooner," he said. "I think you got to wait until next year to really see that inflection."

WATCH: ServiceNow shares plummet in extended trading on mixed Q3 results