Matt Kuchar has led title-holders the United States to a three-stroke lead at the World Cup of Golf in Melbourne. Kuchar, who struggled on the opening day at Royal Melbourne, started Friday&aposs second round strongly with birdies on the first two holes and although he could not maintain that rate, the 35-year-old American held on for a three-under 68. That score, combined with Kevin Streelman&aposs two-under 69, saw the USA finish the second day at 10 under overall – three shots ahead of second-placed Denmark and seven strokes clear of Japan and host country Australia. Kuchar was part of the American team that won the last World Cup in 2011 and is looking to become the first man to defend the title since Tiger Woods, who won in both 1999 and 2000. Denmark&aposs Thomas Bjorn is the best-placed individual at eight under overall after a 68, while Streelman is a stroke further back in second. Bjorn started his second round with a bogey on the opening hole but birdies on the 2nd, 3rd and 6th saw the Danish veteran recover. Two more birdies followed on the 13th and 17th holes but a bogey on the 18th meant Bjorn reached the halfway point just a shot ahead of Streelman. Streelman was flying after four straight birdies to begin his second round but a bogey and then a double-bogey on the 8th and 9th holes saw the 35-year-old American stumble. A solid back nine, including a birdie on the 15th hole, saw Streelman avoid any more trouble. Ricardo Santos of Portugal (69) is tied for third on four under overall alongside Australia&aposs Jason Day, who saw three putts lip out on his way to a 70. With Adam Scott fighting back on Friday with a 68 – after starting the tournament with a 75 on Thursday – Australia remain in contention for the World Cup title.