Did a stage kiss spark a real-life romance between Alec Baldwin and Jane Krakowski?

Those who watched Baldwin throw a long, lingering lip-lock on the “Ally McBeal” beauty during a play reading in New York City are convinced the buss was more than make-believe.

Moments after their sizzling kiss, the two left the building together as Baldwin, 45, flirted with and fussed over voluptuous Jane.

“The chemistry between them was so intense that when the elevator arrived for a crowd of people, everyone decided to let the two of them get in alone so they could have their privacy,” a witness told The ENQUIRER.

The two stars were among several actors seated around a table reading lines from a play called “Twentieth Century” when Baldwin suddenly grabbed Jane and kissed her long and hard.

“They reached the part of the play where their characters announce they are getting married,” the source recalled. “But everyone was startled when Alec gave Jane a long, long kiss because the script didn’t call for them to kiss.

“From what everyone could see, they both really enjoyed it, though, and it seemed to ignite a spark in Baldwin.”

Afterward, the two disappeared together into the night, the source said.

Tony Award-winning Jane, 34, played sex-obsessed Elaine on “Ally McBeal.” She’s currently kissing another man, hunk Antonio Banderas, on the Broadway stage every night in the hit show “Nine: The Musical” and has been romantically linked to English lyricist Charles Hart, whose credits include the score for “Phantom of the Opera.”

Baldwin, once married to Kim Basinger, was rumored to have been romancing “Sex and the City” star Kristin Davis.