WASHINGTON - Democrat Hillary Clinton and Republican Donald Trump have each won the most states on the biggest day of the race for the US presidential nominations.
Mr Trump won seven states while his closest rival, Ted Cruz, took three. The third-placed Republican, Marco Rubio, came in with one.
Speaking in his home state of Texas, Mr Cruz urged other Republicans to quit the race and join him against Mr Trump.
Democrat Bernie Sanders had wins in four states.
Super Tuesday saw 11 states voting, from Massachusetts in the east to Alaska in the north-west. A 12th state, Colorado, held a caucus - won by Mr Sanders - but does not actually select its delegates until April.
Tuesday allocates nearly a quarter of Republican delegates, and about a fifth of Democratic delegates, who will elect their respective presidential candidates at party conventions in July. No candidate has yet won enough delegates to secure their party's nomination.
Mrs Clinton, a former secretary of state, and Mr Trump, a property tycoon, entered Super Tuesday as favourites to win the vast majority of states for their respective parties.
The Democratic frontrunner delivered her victory speech from Miami, having moved her campaign to Florida for the primary there on 15 March, in common with other candidates.
She appeared to already be looking towards a potential presidential race against Mr Trump, saying: "The stakes in this election have never been higher and the rhetoric we're hearing on the other side has never been lower."