Merritt (pictured above) produced a faultless performance in the Stade Roi Baudouin to shatter the previous mark of 12.87 set by Cuba's Dayron Robles in 2008.

The American was the stand-out performer in the Belgian capital on a night when Yohan Blake won the 200m in 19.54 – the seventh fastest time ever recorded and only 0.28 slower than he recorded at the same venue last year – and Usain Bolt confirmed himself as the Diamond Race winner with a 100m victory in the relatively conservative time of 9.86.

"My vision was, if I did break the world record, to run 12.85," said the 27-year-old from Chicago.

"12.85 is all over my everything.

"It's in my email, it's the password for my phone."

Merritt has talked in recent weeks of his desire to break the record, having dominated the event this year with the most sub-12.95 seconds performances in a single season.

Yohan Blake after winning the men's 200m at the Diamond League meeting in Brussels

"I was just trying so hard that I thought 'I can't do it'," he continued, adding he had put the world record out of his mind before the race.

Merritt said he had one remaining task before packing his bags for home – to change the pass code for his mobile phone.

After his victory, Bolt commented: "I told my coach I felt lazy and drained.

"I'm just happy as I'm injury-free."

The double 100/200m Olympic champion still planned a final night out in Brussels, however, and was due to perform a DJ set in the early hours of Saturday, having splashed out on nine pairs of jeans earlier in the day.

"Partying is different," he said.

"If you're tired you can just sit down," he said, before dancing before the crowd to a post-race Shaggy concert.

Usain Bolt, centre, wins the 100m at the Diamond League meeting in Brussels

He will now take a six-week break from athletics.

Compatriot and training partner Blake, who took silver twice behind Bolt in the sprints at the London 2012 Olympics and clinched gold in the 4x100 relay, easily won the 200 metres after establishing a big lead on the bend.

In contrast to Bolt, Blake said he could keep running into 2013, although he will be heading back to Jamaica too – despite his jokey claims that he was not a mere earth human but from "somewhere in space".

"I feel like I'm just starting.

"I feel I could go through until next year.

"I could do anything," he said at the end of a "great year" with medals at his first Olympics.

"Next year it will be even better," he promised, adding he too would be joining Bolt at the "Jamaica Party" though more as a dancer than a DJ.

Earlier, Kenya's Emmanuel Kipkemei Bett ran the fastest 10,000 metres of the season in 26min 51.16sec.

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