Murray edges past Johnson into men's semi-final

By Joshua Schneyer RIO DE JANEIRO (Reuters) - Defending Olympic champion Andy Murray reached the semi-finals of the men's tennis on Friday after winning a third-set tiebreak to scrape through a testing encounter against American Steve Johnson. Britain's Murray, the world number two, edged into the last four 6-0 4-6 7-6(2) but was pushed to the limit by the 22nd-ranked Johnson, who came back to win the second set after being brushed aside in the first. The players traded service breaks and blazin