Question: Ikemefula Charles "Ike" Ibeabuchi defeated a boxer who is a two-time what?

Context paragraphs:
Isaac Lester: Isaac "Ike" Lester was mayor of Murray, Utah from 1923–1929.  He was Murray's first mayor to serve three terms.  Lester defeated incumbent Charles Anderson.  Lester's term was noted for improving a lighting system for the city and offering a contract through Utah Power and Light Company for the service.  He was a member of the fraternal order Woodmen of the World.  Prior to his election, he was a Sergeant in 4th Regimental Cavalry in the Spanish–American War and was a chief in the Murray fire department.

Gu Yong-ju: Gu Yong-jo (July 17, 1955 – March 2001) was a boxer from North Korea, who won the gold medal in the bantamweight (– 54 kg) division at the 1976 Summer Olympics in Montreal, Canada.  In the final, he defeated American boxer Charles Mooney.  In 1980, he competed in the featherweight division and lost his first bout to Krzysztof Kosedowski of Poland.

Ike Ibeabuchi: Ikemefula Charles "Ike" Ibeabuchi (born February 2, 1973) is a Nigerian former professional boxer who competed from 1994 to 1999 in the heavyweight division.  He defeated highly ranked contender David Tua in 1997 and future world champion Chris Byrd in 1999.  After compiling a record of 20–0 with 15 knockouts, Ibeabuchi was imprisoned in Las Vegas in July 1999, after submitting an Alford plea.  In November 2015, Ibeabuchi was released from the custody of United States Immigration and Customs Enforcement (ICE) after completing his 16-year Nevada state prison sentence without incident.  He announced his desire to return to the ring to resume his professional boxing career, but was rearrested before a comeback could take place.

Maxie Berger: Maxie Berger (February 23, 1917 – August 1, 2000) was a Canadian boxer who fought as a flyweight, junior welterweight, and welterweight from 1935–1946.  He squared off against many different Hall of Famers including the likes of Sugar Ray Robinson, Ike Williams, Beau Jack, Fritzie Zivic, Midget Wolgast, and Wesley Ramey.  He held the Montreal version of the World Jr.  Welterweight Title in 1939.  His manager was Tommy Dio.  Statistical boxing website BoxRec rates Berger as the 14th best Canadian boxer ever across all weight divisions.

Srisaket Sor Rungvisai: Wisaksil Wangek (Thai: วิศักดิ์ศิลป์ วังเอก ; born December 8, 1986), better known as Srisaket Sor Rungvisai (ศรีสะเกษ ศ.รุ่งวิสัย), is a Thai professional boxer.  He is a two-time WBC super flyweight champion, having held the title since March 2017, and previously from 2013 to 2014.  As of September 2017, Sor Rungvisai is ranked as the world's best active boxer in the division by the Transnational Boxing Rankings Board (TBRB) and BoxRec, and second by "The Ring" magazine.  BoxRec also ranks him as the world's fifth best active boxer, pound for pound, and tenth by the TBRB.

Mykola Butsenko: Mykola Butsenko (born 25 June 1991) is a Ukrainian amateur boxer who competes in the -56 kg weight division.  In the quarterfinals of the 2013 AIBA World Boxing Championships he defeated Selçuk Eker of Turkey to win his 1st medal at the World Championships.  He is also a two-time European silver medalist.  He participated at the 2016 Summer Olympscs where he lost his first bout against Mohamed Hamout from Morocco.

Chris Byrd: Christopher Cornelius "Chris" Byrd (born August 15, 1970) is an American former professional boxer who competed from 1993 to 2009.  He is a two-time world heavyweight champion, having first won the WBO title in 2000 after an upset corner stoppage over then-undefeated Vitali Klitschko.  In his first title defense later that year, he lost to Vitali's brother Wladimir Klitschko.  In 2002, Byrd defeated Evander Holyfield to win the IBF heavyweight title for his second reign as world champion.  He made four successful defenses until losing his title again to Wladimir Klitschko in a 2006 rematch.  Byrd's cousin, Lamon Brewster, has a shared history with Wladimir Klitschko: Brewster defeated him in 2004, but lost in a 2007 rematch.

Jimmy McLarnin: James Archibald McLarnin (19 December 1907 – 28 October 2004) was an Irish-Canadian professional boxer who became a two-time welterweight world champion and an International Boxing Hall of Fame inductee.  McLarnin has been referred to as the greatest Irish boxer of all time.  BoxRec ranks McLarnin as the 11th best pound-for-pound fighter of all-time, the second best Canadian boxer of all time after Sam Langford, and the third greatest welterweight of all time.

Ike Weir: Ike Weir (February 5, 1867 – September 12, 1908) was an Irish born American boxer, credited with being the first man to take the Featherweight Championship of the World in a match against Frank Murphy on March 31, 1889 in Kouts, Indiana.  The fight was billed as a World Featherweight Title, and went an astounding eighty rounds, though it was officially declared a draw.  Some sources may credit Weir with taking the World Title as early as 1887 in his knockout title wins over Jack Farrell in Ridgefield, New Jersey on January 24, or Jack Williams in Westerly Rhode, Island, on March 10.  Weir first claimed the title in his win over Farrell.

Cedric Kushner: Cedric Kushner (July 18, 1948 – January 29, 2015) was a South African-born American boxing promoter and manager.  In the late 1990s he was one of the most significant promoters in the sport.  Boxers he promoted and/or managed included Hasim Rahman, Shannon Briggs, Oleg Maskaev, Chris Byrd, Corrie Sanders, Ike Ibeabuchi and David Tua.

Supporting paragraphs: Ike Ibeabuchi Chris Byrd
Answer: world heavyweight champion