While the young Leinster squad announced for that fixture trained together, it was a huge thrill for the fans present to see the Ireland internationals and British & Irish Lions participating in their own pre-season training programmes.
The visit to Dundalk RFC was like a trip down memory lane for one of the province's international stars, Rob Kearney, who was born in Dundalk and raised in the nearby Cooley Peninsula.
"It's so surreal to be back here today and see such a welcome from the locals. For myself, this is where it all began," the Ireland full-back told journalists present.
"Me and (my brother) Dave used to play in blitzes back when we were only Under-8s and Under-10s and the field here brings back a lot of great memories."
The training trips to different counties around Leinster are mutually beneficial for the players and fans alike, with Boyne, Cill Dara, Clondalkin, County Carlow, Dundalk, Edenderry, Greystones, Kilkenny, Malahide, Mullingar, Portarlington, Portlaoise, Tallaght, Tullamore, Wexford Wanderers and Wicklow among the clubs visited in recent years.
Kearney added: "These trips to all of the different local clubs are very important. A few years ago, a lot of people would have considered Leinster to be just a Dublin 'club'. But over the past couple of seasons there's been more of a focus on Leinster being a team for the entire province.
"We've made visits like this further afield and have been able to meet fans in places like Kilkenny, Wexford and Laois. It's important for both the squad and supporters, and it's very enjoyable for the players too."
Like his older brother, David Kearney was equally enthusiastic about the trip north from their Dublin base and is relishing the opportunity to impress new head coach O'Connor in the coming weeks.
"It's great to see such an unbelievable turnout (here in Dundalk). I think it's really important for Leinster as a squad to come down here and come to the open days," he told LTV.
"Rugby on a whole is building so much throughout the county and it's great to see. It's important to come here and interact with the fans who have been so good to us throughout the year."
Commenting on Leinster's approach to the new campaign, the young winger admitted: "I think we just need to take it a week at a time. Obviously last year there was disappointment about getting knocked out of Europe early on. Again that's going to be one of our focuses and retaining the PRO12 trophy will be up there as well.
"We're just going to take it a week at a time and build on from that. It's a bit different this year with Matt in now. It's a new clean slate for lads.
"Games like this (one against Ulster), pre-season games, are the times you get to impress when you start in towards the Rabo season. It's been great to freshen things up again and everyone is raring to go and looking forward to the season."
The Kearneys ended last season as Amlin Challenge Cup and RaboDirect PRO12 winners, with David boosting his international credentials in June by helping the Emerging Ireland team finish second at the Tbilisi Cup.
Rob also chalked up his second Lions tour this summer, albeit with a hamstring injury and Leigh Halfpenny's dominance of the full-back position curtailing his on-field involvement in Australia.
The siblings, having played into June and come back into pre-season later, will await their competitive returns as O'Connor first runs the rule over some of the province's young guns and new signings.
He has picked a youthful line-up for tonight's duel with Ulster at Ravenhill, while there is plenty of interest in how New Zealander Jimmy Gopperth - 'a very talented bloke and very good professional' according to O'Connor - fares in his first start at out-half.
"The guys have worked pretty hard in pre-season and they are desperate to play rugby," admitted the new Leinster boss, whose first competitive test is away to the Scarlets on Friday, September 6.
"The group have spoken over the past couple of days about this (the Ulster match) being an opportunity, and how important it is to take that opportunity.
"Because there is a certain amount of responsibility that goes with wearing a shirt and I'm sure those blokes will do us proud.
"The game against Ulster is all about attitude. It's about making sure the guys know the system with and without the ball and they bring the attitude."