Question: The father of Alonso López defended what title twice before retiring?

Context paragraphs:
Ricardo López (boxer): Ricardo “El Finito” López Nava (born July 25, 1966) is a retired undefeated Mexican professional boxer.  As a professional, he defended the Lineal and WBC Strawweight Championship a record 21 times.  He also won the WBA and WBO Championships in the same weight class.  López later won the IBF Light Flyweight Championship and defended it twice before retiring.  He is also the father of undefeated flyweight prospect Alonso López.

Carl Froch: Carl Martin Froch, {'1': ", '2': ", '3': ", '4': "} (born 2 July 1977) is a British former professional boxer who competed from 2002 to 2014, and has since worked as a boxing analyst and commentator for Sky Sports.  He held four world championships at super-middleweight, including the WBC title twice between 2008 and 2011; the IBF title from 2012 to 2015; and the WBA (Unified) title from 2013 to 2015.  At regional level he held the British, Commonwealth, and English super-middleweight titles, and won the Lonsdale Belt in 2006.  As an amateur, Froch won a bronze medal at the 2001 World Championships, and the ABA title twice; all in the middleweight division.

Alonso López: Alonso López (born May 28, 1986 in Mexico City) is an undefeated Mexican professional boxer in the Flyweight division.  He was born in Mexico City, Distrito Federal, Mexico.  He is the son of former World Boxing Champion, Mexican Ricardo López.

Francisco Alonso: Francisco Alonso López (Granada, 9 May 1887–Madrid, 18 May 1948) was a Spanish composer of popular theatre music and zarzuelas.

Diego Alonso: Diego Martín Alonso López (born 16 April 1975) is an Uruguayan retired footballer who played as a striker, and the current manager of Mexican club C.F. Pachuca.

Carl Thompson (boxer): Adrian Carl Thompson (born 26 May 1964) is a British former professional boxer who competed from 1988 to 2005.  He won multiple championships at cruiserweight, most notably the WBO title from 1997 to 1999.  Additionally, he held the British title twice, in 1992 and 1999; the European title twice, in 1994 and 2000; and the IBO title twice, in 2001 and 2004.

Ricardo Alonso López: Ricardo Alonso López Encinas (born February 17, 1994 in Hermosillo, Sonora), known as Ricardo López, is a professional Mexican association football (soccer) player who currently plays for León.

David Alonso López: David Alonso López (November 24, 1977 – July 6, 2017) was a professional boxer who went by the nickname of The Destroyer.  David was a Mexican professional boxer in the Middleweight division and was the former IBA Middleweight Champion.

Dan Creedon: Dan Creedon (June 9 1868 - July 10 1942) was a middleweight boxer who challenged for the world middleweight title twice and claimed the title between 1895 and 1897.  Creedon was born in Invercargill, New Zealand but his boxing career developed in Melbourne, Australia.  Like many of Australia's best boxers of this era, Creedon was taught by boxing pioneers Jem Mace and Larry Foley.  He held the Australian middleweight title from 1891 until his departure for America in 1892.  He challenged Bob Fitzsimmons for the world middleweight title in 1894, in what would be Fitzsimmons' last defense of his belt before becoming a heavyweight.  Creedon was knocked out in just 2 rounds.  However, a year later he claimed the world title following his victory over Frank Craig in London.  Creedon defended his claim to the title at least twice, but he is not commonly recognized as a middleweight champion by boxing historians.  He would eventually lose to Kid McCoy, after which his career took a downward spiral.

Pedro López (serial killer): Pedro Alonso López (born 8 October 1948) is a Colombian serial killer, who was sentenced for killing 80 girls, but who claims to have raped and killed more than 300 girls across his native country, then Peru and Ecuador, and possibly other countries.  Aside from uncited local accounts, López’s crimes first received international attention from an interview conducted by Ron Laytner, a longtime freelance photojournalist who reported interviewing López in his Ambato prison cell in 1980.

Supporting paragraphs: Alonso López Ricardo López (boxer)
Answer: IBF Light Flyweight Championship