The new series sees Catherine Tate join David Tennant
Doctor Who's comeback attracted 8.4 million viewers to BBC One, despite fears an earlier timeslot would harm the sci-fi series.
The early figures, which do not include those who recorded the show, compared with 8.71 million viewers for the debut of its previous series.
Last year's figures included those who recorded the programme to watch later.
Writer Russell T Davies had criticised the BBC's decision to show the programme earlier in the evening.
"It's not a time slot I agree with," he said of the show's scheduling at 1815 on Saturday evening.
"I'd rather it went out later [at 1900]. But we've been told that it's a gateway to the whole Saturday night. We'll see on Monday morning what it's like."
Doctor Who was Saturday evening's top-rated programme, but it was left in the shade earlier in the day by coverage of the Grand National, which hit a peak of 10.1 million viewers as joint favourite Comply or Die surged to victory at Aintree.
BBC One's Talent contest I'd Do Anything had 6.8 million viewers, while 7.1 million viewers watched medical drama casualty.
ITV1's most watched entertainment programme was Harry Hill's TV Burp, which attracted 5.5 million viewers.
But it scored a bigger hit with live boxing, with a peak of 5.9 million viewers tuning in to see Amir Khan defeat Danish fighter Martin Kristjansen.