The sunshine and a mouth-watering schedule of three Grade 1 races were to thank for an attendance of more than 19,000, a record high for the festival's opening day.
There were also plenty of celebrity faces in the crowd, including Irish soccer legend Niall Quinn and his former model wife Gillian; solicitor to the stars Gerald Kean and fiancé Lisa Murphy; RTE radio host Sean O'Rourke and comedian Paddy Courtney.
An attendance of 19,459 was recorded, up from 18,605 last year and organisers are hoping that more than 100,000 people will make their way through the gates across the five-day festival this week.
A string of RTE stars, including Deputy Director-General Kevin Bakhurst, enjoyed lunch and drinks in an exclusive suite as guests of Punchestown.
"It's my first day of racing in Ireland," Bakhurst told Independent.ie
"It's an important part of what we do in terms of Irish sport so we are pretty proud of our strong association with horse racing."
GAA man Marty Morrissey is a regular at racing festivals in Ireland and said he was throwing his money behind jockey Ruby Walsh, who has bounced back from injury.
“A couple of smart guys outside said I was going to the wrong pitch -
no goal posts and no dugouts here. There’s always one,” he joked.
He is usually heard and not seen on the airwaves with RTE's flagship morning radio show, but Sean O'Rourke proved that he has fashion credentials when he turned out in a stylish cream suit.
"I dug this out of the back of the wardrobe - its from Marks and Spencers," explained the chatty host. "I got some material recently with the intention of getting more suits made," he added, laughing.
A keen race-goer, former Ireland soccer star Niall Quinn proudly showed off his pretty wife as they made their way to a hospitality suite where he was playing host to friends and acquaintances.
"I will be back here on Friday with my girlfriends for Ladies Day," explained Gillian. "I don't think my liver could cope with more than two days."
Olympian Cian O'Connor and his wife Ruth enjoyed a break at the racecourse as they left their 8-month-old son Ben with her mum.
"I have a big competition in France on Friday so Ruth deserves a break and this is a big festival for us as it is local," Cian told Independent.ie.
Turning out in matching outfits, love-birds Gerald Kean and Lisa Murphy insisted that their marriage plans are still on track as they giggled and held hands, while comedian Paddy Courtney enjoyed a day out with his wife, Fiona Byrne.