If there was any beer company keeping records back in 600 BC, Bahiya- Daruciriya would hold the World Record as the one who took the least time to attain Nirvana.
The story of Bahiya is very interesting. He started as sort of a cheat. People thought that he was a holyman and would give him alms. The sub-plot of how Bahiya got to be mistaken as a holyman was even more interesting: Bahiya was on a ship, it wreaked and he was washed ashore naked. He tied a piece of bark to his body and went around begging for food. And because he walked around almost naked, people thought he was a holyman!
Bahiya survived on those alms and was living quite happily. After a while, he even started to believe that he really was a holyman. This went on happily until he got a visit from Great Brahma (God, Himself) one evening. God gave him a scolding for what he was doing. Apparently, God and Bahiya were best friends in recent past lives and He was upset to see His best friend living life as a cheat.
After the good scolding, Bahiya decided that he wanted to seek the true teaching. At the recommendation of Great Brahma, he went to the town of Savatthi to ask the Buddha for advice.
It was said that the Buddha knew, from reading the mind of Bahiya, that he was highly cultivated in a past life and he was about this close to Nirvana. So the Buddha uttered one verse to him. It went something like:
It was a very profound verse. Immediately after hearing this verse, Bahiya broke through the final barrier and attained Nirvana on the spot!
Unfortunately, Bahiya's story ends here. He was killed by a charging bull a few hours after his Nirvana.
Verse 101 of the Dhammapada (ie. Verse 2 of the "Thousands" chapter) was spoken in reference to this event.
The Buddha was telling his disciples that Bahiya attained Nirvana after hearing just a single verse. One monk asked how it is possible that a single verse can lead one to Nirvana. The Buddha answered,