The pair, feted as two of Hollywood's best known comic stars, were both named Best Actress at last night's Critics' Choice Movie Awards - Streep for her role as Julia Child in Julie and Julia, and Bullock for The Blind Side, to be released in the UK in March.
Each was given the chance to make an acceptance speech, but it was the moment in-between that had everyone talking, after they staged a mock rivalry.
Very friendly rivalry: Critics' Choice Movie Awards host Bradley Cooper looks on as Meryl Streep and Sandra Bullock lock lips on stage
As Bullock took to the podium after Streep's speech, she yelled: 'This is bull***!'
The glamorous stars then proceeded to face up to one another in mock anger, before sharing a kiss on the lips.
Afterwards, the Miss Congeniality actress, 45, told the audience: 'Meryl's a great kisser.'
On a more serious note, she added: 'This is an honour. It is a great honour to be in the company of the extraordinary women I was so lucky to be nominated with, because this one here inspired me to do everything better.'
Mock-anger: After Streep's acceptance speech, Bullock yelled: 'This is bull****!' before pretending to face up for a fight
Comic greats: Streep continued to poke fun at Bullock as she took to the podium to accept her Best Actress award
Streep, 60, credited Julie and Julia co-star Stanley Tucci, who also worked with her in The Devil Wears Prada.
'I love acting and I love to work and I love food and I love sex — so did Julia Child, so it wasn't that much of a stretch,' she said.
'I want to thank the embarrassingly gifted Stanley Tucci — he knows why. And we're so lucky to do what we do and to give back and I hope we all do it this week. I'm really very grateful.'
Miss Congeniality: The pair, who tied as the Critics' Choice Best Actress, later posed graciously with the single award, proving the rivalry was all in jest
Both actresses have been making an impact on the film industry in recent years. Streep, with her latest release It's Complicated, has proved that there is a market for older women as romantic leads, while Bullock's latest film The Blind Side has already become the first film release in history to make more than $200 million with only one female A-list star to support it.
Also flying the flag for female talent in Hollywood was Kathryn Bigelow, who became the first woman to take home the Best Director award.
The Point Break director, 58, beat Avatar, Inglourious Basterds and Precious with her film The Hurt Locker, which is set among an elite bomb squad in Iraq.
