Despite disappointing Irish fans after cancelling his 2005 Slane gig, the 'Slim Shady' star (36) redeemed himself with an unforgettable performance on the main stage.
He was given a rousing reception from the throngs of enthusiastic revellers, who showed they still had plenty of energy at the end of three long days.
And there was no repeat of the delay that happened when he played T In The Park the previous night, where he was 50 minutes late taking to the stage.
Clad in black shorts, a white T-shirt, a black hoodie and a black baseball cap, the punctual performer started his set at exactly 10.20pm.
"There was a brilliant buzz, the crowd just went mental when he came out," said an onlooker. "The cheers were deafening from the audience and he was definitely the festival highlight for a lot of people."
He performed songs from his new album Recovery as well as some of his best known hits as he brought the festival to a memorable close.
However, organisers were taking no chances when it came to possible flashpoints ahead of the star's eagerly-awaited gig.
Unprecedented security measures were implemented for the third day of the popular Kildare festival, attended by 75,000 revellers.
All ticket holders were frisked with security staff also using metal scanners at the entrance to the racecourse.
Overall, music promoters MCD hailed the event as a rousing success -- and said Eminem was well worth the wait.
It's been seven years since he played Ireland and five since he cancelled his Slane Castle appearance due to nervous exhaustion, which allegedly cost MCD €2.1m. The case was eventually settled out of court in 2007 for an undisclosed amount.
But all was clearly forgiven and forgotten last night, judging by the reaction from his mud-splattered Irish fans.
"I think he's twice as good tonight," revealed MCD's Justin Green. "There was a huge amount of interest from people looking forward to seeing him and a real buzz about the gig."
Meanwhile, other big-name acts on the final day included Faithless, Mumford & Sons and Paolo Nutini.
The Prodigy were keen to sample some traditional fare during their stint here and requested some hearty Irish stew before going on stage.
The previous night saw Muse, Calvin Harris and Black Eyed Peas headlining at the rain-splattered festival.
Flame-haired crooner Florence Welch also gave an acclaimed performance on Saturday, despite the driving rain.
The weather finally gave festival-goers a break with some sunny spells on the last day after two days of battling mud baths around the site .
There was no risk of anyone missing the World Cup final clash either, with soccer fans watching Spain beat Holland 1-0 on a massive 100sqm screen erected at the Nokia Live Stage.
- Pals drank a toast to Gerry with his favourite tipple
- Stars don glam wellies to rock out in style
- Hit-run suspect accused of ramming patrol cars
- Black Eyed Peas party hard at Krystle after storming Oxegen