Going into the bout as an unknown he was heavily written off by many as Khan was the Olympic silver medalist at the time however Watson managed to score a knock down and only lost on a close points defeat.
An early clash of heads had caused a cut above Nuumbembe's left eye which eventually got so bad that the corner could not stem the flow of blood and so handed Watson victory.
[6] Watson rebounded from the defeat to O'Donnell with a points win over journeyman Matt Scriven 21 August 2009 and a second round stoppage of Swiss boxer Riad Menasria on 27 November 2009.
Prior to the fight with Menasria, Watson had said that he was looking to compete at light welterweight in the future and wanted to meet reigning British champion Lenny Daws.
Given just two days notice Watson stepped in to fight Ugandan boxer Badru Lusambya on 16 April 2010 for the light middleweight version of the Commonwealth belt.
His opponent, the Ghanain journeyman Stephen Okine was stopped in the fifth round on the undercard of a bill that saw former victim Matthew Hatton retain his European title with a victory over his mandatory challenger Yuriy Nuzhnenko.
The fight, on the undercard of Amir Khan's contest with Paul McCloskey was stopped in the fifth round when Purdy caught Watson with a right hand to the jaw to win the British title.