Donald Trump on Wednesday became the presumptive Republican presidential nominee after a decisive win in Indiana that forced his nearest rival Ted Cruz to quit the race and the controversial billionaire was poised to clash with Democratic front-runner Hillary Clinton in the November polls. Clinton, however, suffered an upset defeat at the hands of Bernie Sanders in Indiana but the outcome was unlikely to slow the 68-year-old former secretary of state's march to the Democratic nomination. By becoming the presumptive nominee, Trump, who joined politics only last year, has scripted history as he is now on course to be the first standard-bearer of the party since Dwight D Eisenhower, a five-star general and the commander of Allied Forces in Europe during World War II, who had not served in an elected office. "I am honoured to be the presumptive nominee for the Republican Party. It is time to unite our party and defeat Hillary Clinton," 69-year-old real estate tycoon, unpopular with many in his own party, said in a message to his supporters after winning the Indiana primary.