Peak viewing reached 7.7 million with a 34.6% share.
While this was four million down on the launch of the last BBC series, it beat the three million that Jay Hunt, C4's creative chief, had said was needed for the show to break even.
At its peak, the now Mary Berry-less show attracted 6.8 million viewers. "I am delighted millions watched the new team put 12 magnificent bakers through their paces".
The Great British Bake Off: An Extra Slice airs tonight at 10PM on Channel 4.
Despite the drop in viewership, Channel 4 - which generally has a lower audience share than BBC1 - appears pleased with the number. The company also has an exclusive first negotiation position with Love Productions for the global distribution of future seasons of The Great British Bake Off.
During the Edinburgh International Television Festival last week, Hunt said she would be "absolutely delighted" if the new series of Bake Off was watched by "five, six, seven million" on the channel.
Perhaps unsurprisingly it's become Channel 4's biggest show of the year, racking up nearly double the viewers over their previous victor, Diana: In Her Own Words, which managed 3.5 million.
The Great British Bake Off continues on Tuesdays at 8pm on Channel 4.
Tuesday night's programme - presented by Bake Off veteran Paul Hollywood alongside new hosts Prue Leith, Sandi Toksvig and Noel Fielding - included more than 15 minutes of adverts and ran for 75 minutes in total.
Moving to commercial broadcaster Channel 4 from the advertising-free BBC has meant extending "The Great British Bake Off's" time-slot to an hour and 15 minutes to incorporate 15 to 17 minutes of advertising while retaining the show's previous length.