Posh “welled up” when ex-England footie captain Becks heaped praise on his “role model” partner in front of 100 guests, including her fellow Spice Girls.
The dad of four, 48, also filmed her singing with her bandmates on Saturday night – the first time all five are believed to have been together since 2018.
Son Cruz, 19, who has recently launched a music career, belted out a cover of their 1996 hit Mama at Oswald’s in Mayfair, central London.
Victoria, who has a broken foot, was eventually piggybacked by David out of the private members’ club at 2.30am, among the last to leave.
They got into a waiting car with kids Brooklyn, 25, Cruz and Harper, 12.
A source said of the bash, believed to have cost around £250,000: “David told the party how Victoria’s always been a huge inspiration to him.
“He talked of what an amazing role model she is and what an incredible mum she has been.
“The kids also did speeches – it was very informal but they spoke of how grateful they are for everything she’s done for them.”
Guests enjoyed steak, sea bass and Italian-style sharing platters plus £500 bottles of bubbly before hitting the dancefloor.
Posh, Scary, Sporty, Ginger and Baby Spice pulled off a routine to 1997 hit Stop which Victoria shared online.
She posted: “Best night ever! Happy Birthday to me! I love you all so much! #SpiceUpYourLife.”
Sources said the band – who last performed as a five-piece at the 2012 Olympics – were the “life and soul of the party”.
One added: “They had to make up for lost time – and they did exactly that. The girls were having the time of their lives.”
Other hits Wannabe, Say You’ll Be There and Who Do You Think You Are also featured on the playlist as A-list guests including actor Tom Cruise partied late into the evening.
Movie stars Eva Longoria — Harper’s godmother — and Salma Hayek also danced to salsa music with Jennifer Lopez’s ex-husband Marc Anthony, who is Cruz’s godfather.
David and Victoria’s son Romeo, 21, left around 2am while Spice Girls Mel C and Emma Bunton exited hand in hand after Geri Halliwell.
Yesterday Mel B who was joined by hairdresser fiancé Rory McPhee, posted a video online, adding: “About last night #tourdatescomingsoon.”
Brooklyn’s wife Nicola Peltz was unable to attend, but shared an image of her with mother-in-law Victoria.