Dublin - Warren Gatland's 100th Test in charge of Wales will taste doubly sweet if it delivers victory over Ireland in what former Irish star Shane Horgan labels the "grudge match of the Six Nations".
Gatland felt hard done by when he was not kept on as Ireland coach with his Irish assistant Eddie O'Sullivan replacing him in 2001 after three years in the role.
Now the Wales coach has the chance to end Ireland's Grand Slam hopes and inflict the hosts' first Six Nations home defeat since Joe Schmidt took over after the 2013 Six Nations.
Adding extra spice, Horgan said, is that Gatland and Schmidt are two of the men in the running to be next All Blacks coach.
"There is a bit of history (Gatland and Ireland) and if there is a grudge match in the Six Nations then this is it," Horgan said.
"This is definitely the saltiest match of the Six Nations."
Horgan, who made his Test debut for Ireland under Gatland in 2000 before going on to win 65 caps and play three Lions Tests on the 2005 tour of New Zealand, says both sides have a certain antipathy towards each other.
"Wales feel Ireland don't respect them and the Irish are wondering why Wales haven't succeeded in Europe," said 39-year-old Horgan, who is now a lawyer in London and a respected TV pundit.
"But then when you look at their records it is Wales who have more Grand Slams. The two sides are wondering why we can't have both the Grand Slams and European glory."
Horgan, who formed a stunning backline with the likes of Gordon D'Arcy and Brian O'Driscoll which garnered Ireland three Triple Crowns under O'Sullivan until the ill-fated 2007 World Cup campaign, believes Saturday's duel between Gatland and Schmidt will be as compelling as the action on the pitch.
"He (Gatland) is very focussed on this match in particular," said Horgan. "In terms of a record, he is on at the very least parity with Joe Schmidt.
"There is a story within a story here too as potentially they will both go back to New Zealand post the next World Cup and both have eyes on the All Blacks job."
Horgan, who was a two-time winner of the European Cup with Leinster, says clearly both men are not keen to talk up the other's successes.
"Gatland was asked whether Ireland, as many say, have been the most impressive team this tournament and replied 'no' and Schmidt for his part has brushed aside Gatland's achievements," said the former wing.
Whilst Gatland, 54, may still harbour a grudge at the way he was treated by the Irish rugby bosses, Horgan believes he has channelled his disappointment into proving a point.
"Gatland was certainly not happy with the way it (his spell with Ireland) ended," said Horgan.
"They (the IRFU) had to be fair, gave him his first start as a national coach at a very young age (he was 34 when he took the job, leaving the least fashionable of the four Irish provinces Connacht).
"But he left with a bad taste in his mouth. He was under the impression he had been undermined by senior players at the time and by Eddie O'Sullivan and there is a certain amount of truth to that.
"However he has evolved as a coach, his traits of building a team unit rather than a sophisticated approach has worked with both the Lions and Wales."