In Brussels, he was pushed all the way by European record-holder Mahiedine Mekhissi-Benabbad, but the Kenyan pulled out his first sub-eight-minute performance to secure the Diamond Race title.
Led through the first 1000m in 2:38.41, Mekhissi-Benabbad was keeping close to the pacemaker before Birech took up the running and went through 2000m in 5:21.31, with the tempo slipping just outside eight-minute pace.
Determined to become the 11th member of the sub-eight-minute club, Birech pushed the pace in the closing kilometre, opening up a gap on Mekhissi-Benabbad before the final lap.
The 21-year-old Kenyan continued to pull away from his French rival and stopped the clock at 7:58.41, taking him to 10th on the world all-time list.
Mekhissi-Benabbad had to be content with a season’s best and European lead of 8:03.23. In third, USA’s Evan Jager set a North American record of 8:04.71.
“I felt strong before the race,” said Birech. “My aim was to run under eight minutes and I did it. I have reached all my goals this year: to win the Diamond Race, become African champion and run under eight minutes.”
Fellow Kenyan Mercy Cherono did what was required – beating world indoor champion Genzebe Dibaba – to win the Diamond Race in the women’s 3000m.
A large group was huddled together for much of the race and it was only on the last lap when the real racing began.
European 1500m champion Sifan Hassan led at the bell with 2011 world 1500m champion Jenny Simpson on her shoulder and Cherono down in seventh. With 200 metres to go, Cherono began to make her move and she kicked hard as she entered the home straight.
The world 5000m silver medallist did just enough to overtake Hassan, taking the win in 8:28.95. Hassan found some consolation in the fact she set a Dutch record of 8:29.38, becoming just the second woman in history after Maryam Yusuf Jamal to have personal bests below 2:00 for 800m, 4:00 for 1500m, 8:30 for 3000m and 15:00 for 5000m.
Dibaba finished third in 8:29.41. In fourth, Simpson set a personal best of 8:29.58, just 0.35 ahead of US compatriot Shannon Rowbury, who also dipped below 8:30.
Kiplagat defeated but does enough
The men’s 1500m was one of the tighter Diamond Race competitions coming into Brussels and it did not disappoint.
World champion Asbel Kiprop, world leader Silas Kiplagat and world indoor champion Ayanleh Souleiman were all in contention for the Diamond Race victory. Olympic champion Taoufik Makhloufi was also in the race and was always in a good position.
Paced through 800m in 1:52.99, Ethiopia’s Aman Wote was in the lead with 300 metres to go. Makhloufi then moved to the front with half a lap remaining, only for Kiplagat to kick hard.
The Kenyan came close to catching the Algerian, but Makhloufi held on for the win in 3:31.78, just 0.02 ahead of Kiplagat.
The fast-finishing Souleiman was just a further 0.02 behind. Nevertheless, by beating his top two rivals, Kiplagat maintained his lead in the Diamond Race.
World champion Eunice Sum had her lowest finish in an 800m race this year, but it mattered little to a woman who had already done enough earlier in the season to win the Diamond Race.
USA’s world bronze medallist Brenda Martinez was the surprise winner, bursting into the lead with 200m to go and holding off a strong challenge from Lynsey Sharp and Sum to win in 1:58.84.
Sharp clocked 1:58.94 in second place with Sum in third but given the same time.
On the 15th anniversary of Noah Ngeny’s world 1000m record, the Kenyan’s mark went unchallenged in the non-IAAF Diamond League event.
After being paced through 800m in 1:48.8, the Polish pair of Adam Kszczot and Marcin Lewandowski led coming into the home straight.
World 800m champion Mohammed Aman then made his move and although it was enough to catch Lewandowski, he could not quite reach European 800m champion Kszczot before the line.
Kszczot won in a national record of 2:15.72, just 0.03 ahead of the Ethiopian record set by Aman, with Lewandowski was just a further 0.04 behind in third.