Ted Cruz wins Texas Senate run-off election
A Tea Party Republican has beaten an establishment rival in a closely fought, expensive US Senate run-off election in Texas.
In the final vote, Ted Cruz led Lieutenant Governor David Dewhurst 57% to 43%.
The candidates fought for the seat of outgoing Senator Kay Bailey Hutchison.
The Republicans secured a majority in the US House of Representatives in 2010 and are seeking control of the Senate in November's election.
The Texas Senate seat is considered a safe one for Republicans, but correspondents say it is noteworthy that Mr Cruz, who is backed by the Tea Party, has been successful in the primary process.
His victory comes on the heels of victories for other Tea Party-backed candidates competing against veteran Republicans in state primaries in Indiana and Nebraska.
"Tonight is a victory for the grassroots," Mr Cruz said in his acceptance speech. "It is a testament to Republican women, to Tea Party leaders and to grassroots conservatives."
He also thanked former Republican vice-presidential candidate Sarah Palin for her support.
Mr Cruz, 41, is a lawyer from Houston and was formerly the state's solicitor general. He has never held elected office, but his campaign was endorsed by conservative figures such as Sarah Palin and South Carolina Senator Jim DeMint.
He faced Mr Dewhurst, 66, a wealthy businessman who presided over the Texas state Senate and has served in the US Air Force and CIA.
His campaign had the support of much of the Republican mainstream, including an endorsement from Texas Governor Rick Perry.
It was reported that Mr Dewhurst spent $19m (£12m) of personal funds on the race.
Mr Cruz whose father was born in Cuba and would become the first Hispanic Senator from Texas if - as expected - he defeats the Democratic nominee in November's elections.