The first episode of this year's X Factor series drew an average of 8.7 million viewers on Saturday, almost two million down on last year. The flagship ITV1 show, which aired between 20:00-21:15 BST, was the most popular primetime show, drawing a peak audience of 9.9 million at about 20:45. Last year's launch show audience peaked at 12 million. The show has struggled to retain its ratings success since the departure of Simon Cowell as a judge in 2010. Audiences fell last year, with the show drawing an average audience of 13.1 million, compared with the 17.2 million in the previous year. The contest also endured some strong competition from rival talent show Strictly Come Dancing, though it still gained a higher average audience across the series. Saturday's launch show faced competition from the film Indiana Jones and the Kingdom of the Crystal Skull, and the National Lottery, on BBC One; The Proms on BBC Two; Mission Impossible:II on Channel 4 and NCIS on Five. The show won approximately 42 percent of the available audience - double the number of viewers of the next ranked show. But it was also X Factor's lowest series launch audience since 2006. BBC One's Strictly Come Dancing is not expected to launch until the middle of September. 'Vicious attacks' This year sees the return of 2011 judges Louis Walsh, Gary Barlow and Tulisa Contostavlos - and the addition of former Pussycat Doll Nicole Scherzinger. The Sunday Mirror's Kevin O'Sullivan appeared unimpressed by Scherzinger, "the prattling panellist" whose debut he branded "disappointing". But he called guest judge Mel B's "volley of vicious attacks... the best audition fun since Simon Cowell's Mr Nasty heyday". "All in all, a promising opening salvo," he concluded. Of the contestants, supermarket worker Jahmene Douglas's rendition of At Last stood out for critics and judges alike, alongside Curtis Golden's delivery of Candy Man and a self-penned audition from 16-year-old Ella Henderson. Writing in the Daily Telegraph, critic Michael Hogan said Saturday night's opening episode "still seemed slightly out of step with the national mood". "Maybe it's because we're still full of positivity post-Olympics. Perhaps it's the fact it launched on the hottest day of the year when The X Factor traditionally feels like an autumnal event. "But it's back, it's still a slick machine and once it gathers momentum, we'll be powerless to resist," he added. BBC