PORTRUSH, Northern Ireland, July 18 (Reuters) - China's Li Haotong and American Brian Harman led the British Open second round on eight under par as home favourite Rory McIlroy's rollercoaster ride continued at Royal Portrush on Friday.

One of the longest days was also among the more fickle in the 165 years of this major. Five players from five countries tied for the lead at 4-under 67, the biggest logjam in this championship since 1938.