An audience of 1.8m viewers saw Des Lynam take over from the late Richard Whiteley as the host of Channel 4 daytime quiz Countdown.
Carol Vorderman and Des Lynam teamed up for the first time
The number of people tuning in for Monday's edition was the show's highest since last year's Christmas special.
The TV critics deemed Lynam's debut a qualified success, with one calling him "a little glassy-eyed and jittery" but predicting he would be a success.
The ex-sports presenter said last month that he was nervous about taking over.
The Countdown Christmas show received 1.8m viewers on 17 December. It last had an audience of 2m in January 2004.
Former Countdown champion Andy Bodle, who reviewed Lynam's debut for the Guardian, said the new host had "the dignified but slightly desperate air of Brad Pitt after having accidentally wandered into a Star Trek convention".
"If there's one thing that renders Lynam less qualified to present the show than his predecessor, it's that he lacks the common touch," he said.
Vorderman and Whiteley's double act was a hit with afternoon viewers
Bodle said the new host, who is famed for his calm presenting style, needed to show "a little fallibility" to feel "more at home" on the show.
The Scotsman newspaper said the former Grandstand presenter showed "natural confidence" but had "the air of a man who would rather be at Wembley than the Countdown studio at Granada Yorkshire in Leeds".
The show was followed by Noel Edmonds' return to TV presenting with Deal or No Deal.
The Independent's Thomas Sutcliffe said: "If I were taking bets I'd say that Des will still be there after Noel has moved on to other projects."
Lynam told the Radio Times that he would be a different host from the "national treasure and much loved" Whiteley, who died in June.
Whiteley presented Countdown for 23 years from its start until his death aged 61 just days after having heart surgery.
The words and numbers game was the first show to air on Channel 4 when it began in 1982.