Roger Federer is through to the final of the ATP Halle tennis tournament for the 10th time. In the singles semi-final at Halle, Germany on Sunday, he defeated Croatian Ivo Karlovic in straight sets 7-6, 7-6. The Swiss, who has won the title seven times, will go on to face the winner of the second semi-final between Japan's world number five Kei Nishikori and Italy's Andreas Seppi. World number two Federer is chasing a 15th title on grass as he warms up for Wimbledon, which begins on June 29.