Natasha Jonas and Mikaela Mayer have comfortably grown into the welterweight division.

Making weight was never going to be a concern, as both were under the limit for their Sky Sports/ESPN+ main event from M&S Bank Arena in Liverpool, England. Jonas was 146 pounds for the first defense of her IBF welterweight title in her hometown. Mayer was 146.3 pounds in her bid to become a two-division champ.

Jonas (14-2-1, 9KOs) made a three-division jump to win her first major title in a February 2022 second-round knockout of Chris Namus to claim the WBO junior middleweight title. The feat came after the 2012 Olympian for Great Britain came up just short in title bids versus then-unbeaten WBC junior lightweight beltholder Terri Harper and undisputed lightweight champion Katie Taylor.

Two more titles were collected at junior middleweight in a 2022 Fighter of the Year-worthy campaign for Jonas. All three of her fights at the weight came well below the divisional limit, which made for an easy transition to welterweight. 

Jonas was 146.3 pounds in an eighth-round knockout of Kandi Wyatt to win the IBF welterweight title last July 1 in Manchester. Her weight on Friday was her lightest since moving up for her two-division title run.

Mayer (19-1, 5KOs) has now hit a career-heaviest weight for the third straight time.

All have come after she left behind the junior lightweight division, where she previously held the IBF and WBO titles. Her reign ended in a bitter ten-round, split decision defeat to Alycia Baumgardner in October 2022. 

Two wins have followed, one each at lightweight and just above the junior welterweight limit. Saturday will mark the fourth division in as many fights for Mayer. All four have come in the U.K. for the Los Angeles-born boxer who represented the U.S. in the 2016 Rio Olympics and now lives and trains in Vegas. 

Below are the weights for the full undercard.

Jack Cullen (22-4-1, 10KOs), Little Lever, Lancashire, 167.3 pounds vs. Zak Chelli (14-2-1, 7KOs), Fulham, London, 166.3 pounds—12 rounds, super middleweight

Karriss Artingstall (5-0, 1KO), Macclesfield, Cheshire, 124.3 pounds vs. Lila dos Santos Furtado (9-1, 1KO), Sao Paulo, Brazil, 124 pounds—8 rounds, featherweight  

Aaron McKenna (17-0, 8KOs), Smithborough, Ireland, 168 pounds vs. Mickey Ellison (14-6, 5KOs), Darwen, Lancashire, 171 pounds—10 rounds, super middleweight

Mark Jeffers (16-0, 4KOs), Chorley, Lancashire, 167 pounds vs. Germaine Brown (13-2, 4KOs), Kingston, London, 167 pounds—10 rounds, super middleweight

Jack Massey (20-2, 11KOs), Cheshire, 204 pounds vs. Steve Eloundou Ntere (8-1, 3KOs), Asse, Belgium, 201 pounds—6 rounds, cruiserweight

Mikie Tallon (3-0, 0KOs), Everton, Liverpool, 111 pounds vs. Adamu Yahaya Madenge (23-11-2, 12KOs), Dar-Es-Salaam, Tanzania, 113 pounds—4 rounds, flyweight

Steve Clark (pro debut), Liverpool, 160 pounds vs. Vasif Mamedov, Southampton via Perm, Russia 166.3 pounds—4 rounds, super middleweight

Jake Donovan is a senior writer for Twitter: @JakeNDaBox