A source told Britain's Daily Express newspaper: "Kate looked amazing as usual but even Pete looked really well-dressed for once.
"They had their arms round each other all night and made a very handsome couple.
"As they made their way around the room you could hear Kate saying 'Would you like to see my ring?' again and again."
The couple joined in the karaoke at the ball, serenading each other with 'Come Together' by The Beatles and 'Close To You' by The Carpenters.
Doherty wore a black diamante mask over his eyes - which could have been to conceal injuries he sustained the night before (23.10.06) during a brawl with a photographer in Rome.
A host of stars attended the glamorous Moet and Chandon ball in London, including Scarlett Johansson, Jerry Hall, Elizabeth Jagger, Gisele Bundchen and Erin O'Connor.
Model Lizzie Jagger attended the event in a Harlequin costume and Hollywood beauty Scarlett Johansson looked stunning in a black lace mask and fifties-style dress with a see-through back.