Joseph Deng has broken the Australian record for the 800 metres.
Deng has clocked one minute 43.99 seconds at a meet in Lyon, France, overnight, shaving 0.01s from Peter Bol's benchmark.
The 25-year-old Deng is a training partner of Bol, who was thrilled to watch the bettering of his benchmark.
Australian athletics agent James Templeton watched Deng's race while trackside with Bol.
"Pete was thrilled that Joe beat his record, Pete was absolutely beside himself," Templeton told the Nine Network.
"We were at the 100-metre mark screaming at him with about 100 metres to go.
"The funny thing was when Joe went across the line it was 1:44.02 and Pete and I were jumping up and down, Pete was jumping up and down.
"And then within 10 seconds they adjusted it to 1:43.99 and Pete was jumping up and down even more.
"He was absolutely rapt, he was beside himself."
Bol then raced the 1500m and recorded a personal best time of 3:34.52, with rising Australian Cameron Myers finishing third in 3:35.01, a national under-18 and under-20 record.