The red-hot favourite for our final race of the day is the Willie Mullins-trained Gaillard Du Mesnil ridden by his son Patrick, a regular in the winners' enclosure at Prestbury Park.

Image source, Getty Images

The horse has the stamina, having finished third in last year’s Irish Grand National and Mullins senior believes he is hard to oppose.

Chemical Energy ran well at Cheltenham in October and jockey Jamie Codd is another to have enjoyed Festival success over the years.

Right, how have we all done today? My tip for the day finished dead last in the first, start as you mean to go on and all that.

One more race to go on what has been a superb opening day of racing.

Image source, PA Media

Winning jockey Michael O'Sullivan, speaking to Racing TV: "Unbelievable. He travelled everywhere for me. I was always getting there.

"My dad is amazing. He never pushed me too much and when he saw I showed interest he put a lot of time into me and it is great it is paying off."

My colleague here in the office, Matt Henry, is kicking himself after failing to back his namesake in that race. He's Not So Jazzy Matty right now.

You don't see enough horses called Gary for it to be an issue for me.

1 Jazzy Matty (Michael O'Sullivan) 18-1

2 Byker (P Byrnes) 6-1

3 Risk Belle (L P Dempsey) 10-1

4 Sundial (S D Torrens) 18-1

21 ran

Charlie Poste
Former jump jockey on BBC Radio 5 Live Sports Extra

It’s been a fantastic day for Michael O’Sullivan announcing himself on the big stage. He has been earning rave reviews in Ireland for his riding. He dug really deep and got headed and battled back.

That was a shrewd jockey booking by trainer Gordon Elliott

It is a second win for jockey Michael O'Sullivan after he won the first race of the day too.

Jazzy Matty comes through in the final stretch to take the win!

He pips two other horses by a nose.

Bad continues coming down to the last.

Rachael Blackmore, on Bad, moves up to the front now as they come down to three from the finish. Jazzy Matty is in the mix.

Samuel Spade jumps the second in the lead. The rest of the field also clear the hurdle with no issues.

Penultimate race and finally here we go!

No joy at take two either with a few side on as the flag goes up.

Third time lucky?

They're a bit too eager to get off as the flag is raised so they have to take a turn and come back round for a standing start.

Frank Keogh
BBC Sport at Cheltenham

John Hunt is calling the horses home in all 28 races for BBC Radio 5 Sports Extra.

His selection PERSEUS WAY (9-1) runs in the Boodles Juvenile Handicap Hurdle at 16:50 GMT.

"I thought he would get a stiffer penalty from the handicapper after a great run in the Adonis Hurdle at Kempton when he was unlucky not to win," he said.

After starting his career on the Flat, Byker has made a successful switch to hurdles and could give trainer Charles Byrnes a Festival success along with son Philip who takes the ride.

Tekao leads the betting market in a big field for Willie Mullins and jockey Mark Walsh.

And could the former French challenger Bad be good for Rachael Blackmore on his first start for trainer Ben Pauling?

Frank Keogh
BBC Sport at Cheltenham

Great shot here from earlier by BBC Radio 5 Sports Extra producer Rob Nothman.

Jockey Nico de Boinville salutes the Cheltenham crowd as he leads Champion Hurdle winner Constitution Hill back to rapturous applause.

Does the racing really have to end? Just two more to go on day one.

Result - Sky Bet Supreme Novices' Hurdle, 2m 1/2f - Marine Nationale (9-2)

Result - Sporting Life Arkle Challenge Trophy Novices' Chase, 2m - El Fabiolo 11/10 Fav

Result - Ultima Handicap Chase, 3m 1f - Corach Rambler 6/1 Fav

Result - Unibet Champion Hurdle Challenge Trophy, 2m 1/2f - Constitution Hill 4/11 Fav

Result - Close Brothers Mares' Hurdle, 2m 4f - Honeysuckle 9/4 Fav

16:50 - Boodles Juvenile Handicap Hurdle, 2m 4 1/2f

17:30 - National Hunt Chase (Novices' Chase, amateur jockeys), 3m

Check out the full results here

Image source, Reuters

Honeysuckle owner Kenny Alexander, speaking to Racing TV: "She's not the greatest Champion Hurdler ever but she's one of the bravest. She has guts and is incredibly talented. She had to dig deep today. I am really happy for Henry and his family."

BBC Radio 5 Sports Extra

Winning trainer Henry de Bromhead: "It's the fairytale ending that doesn't normally happen. I am so happy for everyone. You dream of it but this is what she deserves. She is an unbelievable mare. She is so special.

"I think we have had a terrible year with Jack but the support everyone has given us we are really grateful for that."