Question: Brian London lost in 1966 to what professional boxer born 1942
Context: Humberto Tapia Armenta (January 10, 1986 – March 29, 2011) was a Mexican professional boxer born in Tijuana, Baja California.  He was in the Light Welterweight division and was the Inaugural WBC FECOMBOX Light Welterweight Champion. Brian Sidney Harper (born 19 June 1934), known professionally as Brian London, is an English retired heavyweight boxer.  He was the British and Commonwealth heavyweight champion from 1958 to 1959, and twice challenged for the world heavyweight title, losing to Floyd Patterson in 1959 and Muhammad Ali in 1966, both times via knockout.  He was one of a quartet of British boxers, with Henry Cooper, Joe Erskine, and Dick Richardson, who dominated the British boxing scene throughout the 1950s and 1960s. Najai "Nitro" Turpin (December 19, 1981February 14, 2005) was a professional boxer born in Philadelphia, Pennsylvania, USA. Joey "The Jab" Singleton, was a professional boxer born in Kirkby, Liverpool, England.  Born 6-6-1951.  Joey was a light welterweight boxer and won the British title in a distinguished career as a professional. Jack London (real name John George Harper, born 23 June 1913 in West Hartlepool, County Durham, died 19 December 1963) was an English heavyweight boxer.  He was British and Commonwealth Heavyweight champion from 1944 to 1945.  His son, who fought as Brian London, also became British and Commonwealth Heavyweight champion from 1958 to 1959. Muhammad Ali ( ; born Cassius Marcellus Clay Jr.; January 17, 1942 – June 3, 2016) was an American professional boxer and activist.  He is widely regarded as one of the most significant and celebrated sports figures of the 20th century.  From early in his career, Ali was known as an inspiring, controversial, and polarizing figure both inside and outside the ring. Sean Hughes (born 5 June 1982) is a British professional boxer born in Pontefract, West Yorkshire.  He now resides in South Shields.  He is most notable for defeating the then British Super Bantamweight Champion, Esham Pickering in December 2007.  Pickering was on the verge of stepping up to European and even World level before the bout and it was expected to be a routine victory for the Newark champion.  However, at the Nottingham Arena in front of the SKY TV cameras Hughes won a points victory over 8 rounds. Gurcharan Singh (born April 10, 1977) is an Indian Professional boxer born in Rurewal, Punjab and currently settled in Philadelphia, USA. Dick Richardson (1 June 1934 – 15 July 1999) was a heavyweight boxer from the Maesglas area of Newport, Monmouthshire, Wales.  He held the European heavyweight title from March 1960 to June 1962.  In all, he won 31 of his 47 professional bouts, losing 14, with two drawn.  He was one of a quartet of outstanding British heavyweights in the 1950s and early 1960s, along with Henry Cooper, Joe Erskine and Brian London, who held out the possibility of a British heavyweight world champion. James William "Iron" Hague (6 November 1885 – 18 August 1951) was a boxer born in Mexborough, South Yorkshire.  He was the British heavyweight champion between 1909 and 1911.  He fought for the Yorkshire heavyweight title against Dick Parkes at Doncaster on 8 April 1905, winning in the fifth round.  He then went on to beat a steady stream of English heavyweights, many by knockouts.  He was invited to enter the Heavyweight Novice competition held at the National Sporting Club, London in January 1908.  This was a series of fights of three rounds only.  He won this with a series of knockouts.  After a few more wins he was invited to fight Gunner Jim Moir for the English Heavyweight title on 19 April 1909.  He won this in the first round with a knockout, creating a new boxing record for the fastest victory of a title.  His homecoming was a splendid affair with thousands lining the streets of his home town.  He defended the title once against Bill Chase, knocking him out in the sixth round, but lost it on 24 April 1911 to the up-and-coming Bombardier Billy Wells.  This fight was for the first Lonsdale Belt.
Answer: Muhammad Ali