[1] Fonseca fought on the undercard in a super featherweight bout with undefeated IBF champion Gervonta Davis on the 26 August 2017 mega fight between Floyd Mayweather Jr. and Conor McGregor.
[4] On 15 December 2018, Fonseca made his second challenge for the IBF super featherweight title, now held by Tevin Farmer, on the undercard of Canelo Álvarez vs. Rocky Fielding.
Fonseca was once against unsuccessful, losing by unanimous decision with all three judges scoring the bout 117–111 in favor of Farmer.
[5] On 16 November 2019, Fonseca travelled to London, England to face Alex Dilmaghani for the vacant IBO super featherweight title.
[6] In his following fight, Fonseca faced undefeated prospect Ryan García at the Honda Center, California on 14 February 2020.