Last night the 24-year-old double world cross-country champion strode towards the finish line all alone to consign Ondieki's mark of 26min 58.38sec to history, taking more than six seconds off it with a new world record of 26:52.23.
A triumph for Kenya - and for Teddington, where Sigei is based as one of the group of athletes managed by Kim McDonald. Sonia O'Sullivan, a regular training partner of Sigei's, narrowly failed to complete a Teddington double when she won the mile in 4:17.25, just outside Paula Ivan's five-year- old world record of 4:15.61.
Ondieki's record, which represented the greatest advance in the event since Ron Clarke broke through the 28- minute barrier in the same stadium 19 years ago, seemed untouchable. But the bounds of possibility are being stretched again, just as they were after Roger Bannister ran the first mile in under four minutes.
Sigei, who now travels to Nairobi to prepare for the Commonwealth Games, looked for much of the race as if the task was beyond him. After his last pacemaker, William Mutwol, had dropped away with 14-and-a-half laps to go, it was left to this civil servant in the Armed Forces to push on alone. He did so, closing the gap to the world record pace to 0.21sec at 7,000m. At 9,000m he had slipped back to over two seconds off the pace, but his final efforts brought him back into the reckoning.
He entered the final lap needing to run 63 seconds. He managed a 58sec lap still showing no obvious sign of strain. 'I knew I could break the world record after running here last year,' Sigei said. All very simple, then.
Such has been the Kenyans' domination of cross- country that in winning consecutive world titles Sigei has had the work done for him by team-mates. Sigei has won because the Kenyans consider Sigei to be their best runner.
Kenya's domination of the 10,000 event on the track has been of a similar order. Five of the top six 10,000m times last year were down to Kenyans - Ondieki's epochal mark bettered the world record of 27:07.91 set five days earlier by Richard Chelimo, and Sigei earned third place in the standings by chasing home Ondieki at Oslo in 27:16.81. But on this occasion he did without a little help from his friends.
Colin Jackson, who missed the last two domestic meetings as a precaution after feeling a groin strain last Friday, returned in superb shape. Running against the Olympic champion Mark McKoy for the first time this season, he was pushed to victory in 13.23sec.
Jackson had given notice of his intent with an easy 13.20sec in the heats, his fastest time this year, but the weather had cooled appreciably. It was a useful marker for him - McKoy, now a naturalised Austrian, will run in the European Championships.
O'Sullivan, who was seeking her fourth record in 14 days, said: 'I am disappointed. But I know I can run faster. I tired over the last 100 metres.'
Eamonn Martin, denied a 10,000m place here and then offered it at such short notice that he could not alter his plans, seeks a qualifying standard for the European Championships and Commonwealth Games tomorrow, having obtained an entry to the Goodwill Games.
Although there is some reluctance among the British selectors to extend deadlines beyond 20 July, Britain's chief coach, Malcolm Arnold, said that Martin's performance in St Petersburg will still be considered.
Tom McKean, named in the European Championship team despite indifferent form at 800m, remained indifferent as he finished ninth in 1min 46.20sec. Kevin McKay and David Strang, also Helsinki- bound, were seventh and 10th respectively in a Dream Mile won by Burundi's Venuste Niyongabo in 3min 48.94sec, the fastest time in the world this year.
Rob Denmark was unable to get close to the winner of the 5,000m, Khalid Skah of Morocco, who ran 13min 01.89sec. There is the man who may take the 10,000 metres still further into unknown territory.