Munster and Ulster have each fired their shots at winning away in South Africa, but neither could come home with anything more than losing bonus points.
The four new South African franchises started slowly in the United Rugby Championship, but since their role turned from tourists to hosts in the spring, they've been a force to be reckoned with.
Only one northern hemisphere side has returned with a win; Edinburgh's surprise 21-5 victory against the Sharks in March the only time in 16 attempts that north has beaten south away from home.
This weekend, and next, it's the turn of Leinster and Connacht to try and break Ireland's luck in South Africa.
With games against the Sharks this evening and the Stormers next week, Leinster's schedule has been kinder than others - both Durban and Cape Town are at sea level, meaning they won't have to deal with the additional challenge of altitude.
However, this evening's game at King's Park will throw up reunion with a familiar face, in the form of Leinster's former academy chief Noel McNamara, now on the coaching ticket at the South African side.
"The Sharks in particular, Noel McNamara knows our guys very well," Leo Cullen said.
"We talked in the past about coaches going to other teams, so that bit of inside knowledge is always a threat.
"The playing power they have you've seen in recent weeks, the front row of Ox Nche, Bongi [Mbonambi], [Thomas] du Toit, those three are all very powerful. I could go through their whole team, they have a lot of quality."
On paper, the Sharks would have the strongest collection of household names.
Along with Nche and Mbonambi as Cullen mentioned, they can boast Springboks skipper Siya Kolisi (above), Makazole Mapimpi, Jaden Hendrikse and Aphelele Fassi, with a hefty second row of Le Roux Roets and former Munster lock Gerbrandt Grobler.
The defending champions come into the two-game tour with a 10-point lead at the top of the table, having won 12 of their 15 games.
However, with one eye on the playoffs, and on the quarter-final of the Champions Cup in two weeks, Cullen has left the bulk of his Six Nations contingent behind in Dublin.
The touring squad is a blend of young prospects and veterans, with Rhys Ruddock captaining a side that gives a debut to Brien Deeny in the second row, but also contains international quality in the likes of Andrew Porter and Ronan Kelleher.
Ruddock says they are braced for the extra physicality the South African franchises are famous for.
"Absolutely massive, probably a level you rarely would experience," he said of the physicality.
"It’s going to be a huge challenge. Even when we played the Lions at home, that physically was a huge challenge, and you saw areas like the setpiece and the contacts and collisions were huge.
"That was in the RDS, so playing against Sharks and Stormers, who are pushing for playoff spots, the way they’ve been playing they’re likely to be in the mix.
"There’s a lot to play for, for them, so we can expect it to go up another notch from there. It’s a great challenge for this group, but it’s also a great opportunity to learn some lessons that will stand to us going into the back end of the season."
Heat and humidity is likely to be an issue for Leinster today, with temperatures likely to be in the mid-20C range in Durban.
And Ruddock says while they will continue to try play a quick brand of rugby, they'll also have to box clever.
"Both teams will have a crack and try and play a sort of high-tempo brand of rugby. The weather has a big factor to play, but traditionally the South African teams would be a lot bigger, heavier physical bodies.
"They won’t be afraid to mix it with us, in terms of a more direct game, as well as the pace they have," he added.
While Leinster's touring squad was picked with an eye on later this season, Connacht's was chosen with next season in mind, Andy Friend opting to leave of this summer's departing players at home for the tour.
The western province's season has petered out in recent weeks, with their heavy defeat against Leinster last week ending their Heineken Champions Cup campaign, and although they can mathematically still qualify for the URC playoffs, they would need three wins from their final three games, as well as some favours elsewhere.
Their form against South African opposition has been good in the past, with wins against both the Bulls (below) and Stormers in Galway this season making it eight in a row against SA sides, dating back to 2018.
They begin their tour this afternoon at Emirates Airline Park in Johannesburg against the Lions, who last month came from 14-0 and 21-10 down to beat Munster 23-21.
Similar to Connacht, consistency in performance will likely be the main reason the Lions miss out on the playoffs, but Friend says their ability to stay the course at altitude is the "joker up their sleeve".
"I think they have some tremendous individuals, and if you give them space they’ll really hurt you," he said.
"They also enjoy the fact they play here at altitude, it suits their game, and what we’ve seen over the last couple of months is that teams that come here may be in the hunt until the 50th or 60th minute, and tend to drift away.
"We’re very conscious of it, it’s something I would imagine the Lions management and players have, that joker up their sleeve, that the last 20 minutes team tend not to be able to handle altitude as well.
"They have threats across the park, a nice big forward pack, if you give them space their quick backs and big back rowers can run through and hurt you. It’s about managing the ball, making sure we respect that, and when we can, impose our game style upon them and see if they can handle that."
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