Ted Cruz has won the Republican presidential caucuses in Kansas and Maine, strengthening his position as the prime alternative to Donald Trump.
The result adds to Mr Cruz's previous victories in Iowa, Alaska, Oklahoma and his home state of Texas.
Although the outcome may have slowed Mr Trump's momentum slightly, the brash billionaire still came out top in the Republican nominating contests held in Louisiana and Kentucky - furthering his lead in the delegate count.
It was not a "Super Saturday" for Marco Rubio and John Kasich, fast becoming outsiders for the nomination, who walked away with nothing.
During a speech in Florida after the final result of the night was announced, Mr Trump suggested that Marco Rubio - a rival he has exchanged frequent personal attacks with - should now drop out of the race.
For the Democrats, three states were in play - and Bernie Sanders swept to victory in the caucuses being held in Nebraska and Kansas.
Hillary Clinton was looking to cement her front runner status for the nomination, but only secured a win in the Louisiana primary.
Mr Cruz greeted the news of his Kansas win while in the western state of Idaho, saying: "The scream you hear, the howl that comes from Washington DC, is utter terror at what 'we the people' are doing together.
"What we're seeing is Republicans coming together. What we're seeing is libertarians coming together. What we're seeing is men and women who love freedom and love the Constitution coming and uniting and standing as one behind this campaign."
Both victories are likely to boost Mr Cruz's claim that he is the best bet for establishment Republicans who don't want Trump to become the nominee.
Going into Super Saturday, Mr Trump had already accumulated 319 of the 1,237 delegates needed to win the nomination at July's Republican national convention - comfortably more than Mr Cruz's 231.
Florida Senator Marco Rubio has 110 delegates, while Ohio Governor John Kasich is trailing with 25.
Overall, 155 Republican delegates were at stake during Saturday's voting.
The next big round of voting will come on Tuesday - with Democrats heading to primaries in Mississippi and the large industrial state of Michigan.
Republicans will also be holding a contest in those two states, in addition to caucuses in Hawaii and a primary in Idaho.
