Together with Morné Nagel, Corné du Plessis and Matthew Quinn he won a silver medal in 4 x 100 metres relay at the 2001 World Championships in Athletics.

At the 2006 Commonwealth Games in Melbourne, Newton won a silver medal with the South African team in the 4 x 100 metres relay.

In February 2007 Newton clocked 9.95 seconds in the 100 meters at the KwaZulu-Natal Athletics senior provincial track and field championships in Durban, narrowly beating teammate and training partner Dean Wicks, who clocked 10.00 seconds.

Even Linda Ferns, CEO of Athletics SA, said the application to recognise Newton's time in Durban would be studied.

[2] On 13 February, the time was disqualified for three reasons: 1) Lee-Roy's reaction time of -0.046 seconds is considered too fast by IAAF rules, and therefore indicates he false started, 2) the finish line camera was not properly aligned with the finish line, possible by much as a meter, 3) he was not escorted to drug testing at the stadium, and rather was tested much later at his residence.