SUPERSTAR chaser Douvan was bitterly disappointing as Special Tiara enjoyed his day in the sun in the Betway Queen Mother Champion Chase at Cheltenham.

Unbeaten in 13 previous starts for Willie Mullins, Douvan was the 2-9 favourite to add to his tally in the feature event on day two of the Festival.

Already a dual winner at the showpiece meeting having landed the Supreme Novices' Hurdle and the Arkle Trophy in the last two years, this was meant to be the day Douvan graduated to championship level with honours, but instead those in attendance witnessed one of the biggest shocks in recent memory at Prestbury Park.

The prohibitively-priced seven-year-old was initially well positioned under Ruby Walsh, but the crowd gasped as he stood off the fence in front of the stands and that proved the first of a few uncharacteristically inaccurate leaps.

He was still on the premises racing down the hill, but it was soon apparent his usual spark was missing and he eventually trailed home a well-beaten seventh.

Mullins said: "He was clearly never going and I thought at the top of the hill he'd do very well to win.

"I'm assuming something happened when he put in those huge jumps, which I've never seen him do before.

"I imagine I'll find a physical problem with him."

At the business end of proceedings, the Henry de Bromhead-trained Special Tiara, third in the last two Champion Chases and sixth in 2014, devoured his fences in his customary pacesetting role.

Fox Norton finished like a train from the final fence, but Special Tiara clung on by a head in the hands of Noel Fehily. Sir Valentino was another six lengths away in third.

Fehily, who won the Champion Hurdle on Tuesday, said: "Unbelievable. He's such a great ride, he's everything a two-mile chaser should be. He's a very good horse.

"I didn't think we'd beat Douvan, but I thought I had a great chance of being second. I got over the last and was surprised something hadn't come to me, but I knew he wasn't stopping.

"He has one way of running and that's flat to the mat and jump - I just let him get on with it.

"I've always loved two-mile chasers, the Champion Chase is the one you want to win. To win it is fantastic."

De Bromhead was winning the two-mile crown for the second time following the victory of the popular Sizing Europe in 2011.

He said: "It's an amazing day, I'm just so pleased for everyone involved.

"He seemed in great form coming into it, but it was hard to believe we could win with Douvan and everything else - Douvan had looked so good.

"For our lad, he just tries his heart out and no-one deserves it more."

Colin Tizzard said of the runner-up Fox Norton: "When he jumped the last it looked like he was going to get there.

"Special Tiara has done this for the last few years but to be fair to the horse he pulled out more.

"We had a conversation about this race and Douvan or the Ryanair and I still don't know if we made the right choice.

"He's a fresh horse so he'll go to Aintree next over two and a half miles (Melling Chase)."