Alistair Cragg broke Mark Carroll’s 13-year-old Irish 5000m record with a superb display at the Memorial van Damme in Brussels on Friday evening.
Cragg clocked 13 minutes 3.53 seconds to finish in fifth place at the final Diamond League meeting of the season.
Carroll’s old record of 13:03.93 was set in Berlin back in 1998.
The race was won by Imane Merga of Ethiopia in 12:58.32.
Cragg’s time is almost a four-second improvement on his previous personal best.
Yohan Blake warned Usain Bolt he will be gunning for his Olympic 200 metres crown in London next year after storming to the second fastest time in history.
The 21-year-old upstaged his fellow Jamaican and training partner by clocking a stunning 19.26.
Bolt, who minutes earlier had run the fastest 100m of the year - 9.76 - is the only man to have bettered Blake's time with his world record of 19.19.
A wide-eyed Bolt gave Blake, who took his 100m title at the World Championships in Daegu last month, a congratulatory hug afterwards, but there must surely be an element of concern he will now have a genuine rival over both distances in London.
Blake appeared to take it easy round the bend before powering away down the home straight to take a staggering 0.52 off his personal best, his time well ahead of the 19.40 Bolt ran to win the world title in Daegu.
"Tonight I was aiming to run 19.5. I was expecting something fast but not this fast," Blake said on BBC2.
"The last 40 metres was crazy. I'm like a beast. I just take it out on the track.
"When I saw him (Bolt) run 19.40 at the worlds I knew I could go fast like that.
"I'm looking forward to competing with him next year."
Blake was slow out of the blocks, but his time was still faster than Michael Johnson ever ran.
"That's amazing for me. I'm shocked he did so well," Bolt said.
"I've seem him run a couple of 200m and he's run them badly. I told him to take it easy round the bend. He ran a wild time."
Bolt had been set to take the headlines when he ran his fastest time since 2009 to win the 100m, beating Asafa Powell's previous world-leading time by 0.02.
The 25-year-old, who was disqualified for false starting in the final in Daegu, was neck and neck with Nesta Carter until the 60m mark before pulling away.
There was no slowing down at the finish with Bolt dipping for the line clearly determined to beat Powell's mark and getting a meeting record in the process.
The Olympic champion and world record holder said: "It was never a doubt in my mind I would run fast in these last two races (in Zagreb when he ran 9.85 earlier this week and Brussels).
"Today I was really happy with myself.
"It's (a false start) not going to happen again. I made one mistake and I won't let it happen again."
Kenenisa Bekele sent out a warning to Mo Farah that he will not surrender his Olympic 10,000m title in London next year without a fight by running a world-leading 26:43.16.
The Ethiopian failed to finish in Daegu in his first race in around 18 months because of injury, but today's time knocked Farah's European record of 26:46.57 off the top of the season's charts.
Dai Greene added the Diamond Race title to his world 400m hurdles crown, despite having to settle for second place behind Javier Culson.
The Puerto Rican gained a measure of revenge on the Welshman, who overhauled him in the final strides in the final in Daegu, winning in 48.32s.
Greene, who clocked 48.78, knew second place would guarantee him the overall title and the $40,000 prize that goes with it.
"That was the whole point of me coming here. I've put the hard work in all year and this is my reward," Greene said.
There was disappointment for another world champion, though, Sally Pearson suffering a bad fall in the 100m hurdles.
The Australian, who has been dominant throughout the season, hit the seventh hurdle and crashed to the track, but was able to walk off apparently unhurt.
World 1500m silver medallist Hannah England was fifth as Morgan Uceny, who fell in the final in Daegu, took the victory in a world-leading 4:00.06.
Phillips Idowu, guaranteed the Diamond Race, could also only manage fifth in the triple jump in 16.29m.
World champion David Rudisha won the 800m.
