Des Lynam confesses to being "a little bit nervous" in his first episode of Countdown.
The housewives' favourite says the Channel 4 show will pay respect to his predecessor Richard Whiteley.
Lynam, 63, tells the audience: "I hope I'm not too much of a shock to you. I've got a very difficult act to follow with dear Richard of course, much loved by you all, but I shall be doing my best.
"I'm a little bit nervous," he added. "I hope to get to know the rules in due course - after about 300 programmes I'll crack it I'm sure.
Lynam, who will reportedly be paid around £600,000-a-year to front the teatime show, says it has been a "difficult time for Countdowners".
But the former Match of the Day presenter adds: "We'll pay respect to Richard from time to time, I'm sure, as we go along, many times. I was a great fan of him and he was a lovely man.
Carol, 44, introduces the episode with a "welcome back to Countdown".
She tells viewers: "It's been a very long summer and we've missed you Countdowners and we know that you've missed us because you've told us in your tens of thousands.
"This is the first and only time I'll be saying 'hello and welcome' to you at the beginning of Countdown because we have a boy in the house...you might have seen him before, his name is Mr Des Lynam.
Much-loved Whiteley, the show's anchorman since its inception in 1982, died in June after emergency surgery for a faulty heart valve at the age of 61