Jennings in his early fights, with victories over journeyman fighters such as Lee Molyneux, Brian Coleman and Paul Denton.
On 25 October 2005, Jennings recovered from a 1st round knockdown to go on to defeat Bradley Pryce on points in a defence of his British title.
[1] On 7 April 2007, Jennings defeated Mehrdud Takaloo via a unanimous points decision to win the WBU welterweight title.
The fight was held at the Millennium Stadium, Cardiff on the undercard of Joe Calzaghe's fight with Peter Manfredo Jr. On 2 February 2008, Jennings stopped Ross Minter, son of former World champion Alan Minter, in the 9th of a 12-round contest round en route to defending his WBU title.
On 21 February 2009 Jennings was defeated via 5th-round TKO by the now retired five-time, 3 weight world champion Miguel Cotto for the vacant WBO Welterweight Title in New York's, Madison Square Garden.