Mikaela Mayer moved up one division for a second consecutive fight, this time to face Silvia Bortot at junior welterweight (catchweight of 142 pounds) in a fight she dominated, winning all 10 rounds. And her next fight could also be at a higher weight class. Mayer said during her post-fight interview that she wants to compete at welterweight moving forward.
"I'm ready for that fight [against Jonas]. It's a big jump going from 130 pounds to 147 pounds, but I'm prepared to go to 147 pounds and take on Tasha [IBF welterweight champion Natasha] Jonas straight away," Mayer said. "We're both looking for big fights, we have both solidified our names, ideally I would want it next."
With the victory over Bortot, Mayer moves up one spot to No. 6. Amanda Serrano and Seniesa Estrada also moved up one spot after victories over Heather Hardy and Leonela Yudica, respectively. Alycia Baumgardner was removed from the rankings after testing positive for a banned substance.
"I moved Mikaela up to No. 3 on my list for a couple of reasons. Any time a fighter moves up a weight class, there is risk involved. Mikaela checked all of the boxes in her win Saturday over Bortot -- good lateral movement, pressed the action and countered very well," Charlie Moynihan, ESPN senior managing producer, said. "It was also her fourth fight in 17 months -- hats off to an active fighter. Is her next fight at 147 pounds? Quite possibly. And to borrow an adage from college football coach Prime (Deion Sanders) and Colorado University: "We're coming." So is Mikaela Mayer.
Savannah Marshall, however, was the biggest mover. Marshall gained three spots after her majority decision victory over Franchon Crews Dezurn to become the undisputed super middleweight champion. Crews Dezurn fails to make the top 10 following the loss.
And Jonas makes her P4P debut at No. 10 after defeating Kandi Wyatt to win the IBF welterweight title.
Here's the current top 10.
Note: Results are through Sept. 6.
1. CLARESSA SHIELDS 
Previous ranking: No. 1
RECORD: 14-0, 2 KOs
DIVISION: Middleweight undisputed champion
LAST FIGHT: W (UD10) Maricela Cornejo, June 3
NEXT FIGHT: TBA
2. AMANDA SERRANO 
Previous ranking: No. 3
RECORD: 46-2-1, 30 KOs
DIVISION: Featherweight undisputed champion
LAST FIGHT: W (UD12) Danila Ramos, Oct. 27
NEXT FIGHT: TBA
3. KATIE TAYLOR 
Previous ranking: No. 2
RECORD: 23-1, 6 KOs
DIVISION: Lightweight and junior welterweight undisputed champion
LAST FIGHT: W (MD10) Chantelle Cameron, Nov. 25
NEXT FIGHT: TBA
4. CHANTELLE CAMERON Previous ranking: No. 4
RECORD: 18-1, 8 KOs
DIVISION: Junior welterweight
LAST FIGHT: L (MD10) Katie Taylor, Nov. 25
NEXT FIGHT: TBA
5. SENIESA ESTRADA Previous ranking: No. 6
RECORD: 25-0, 9 KOs
DIVISION: Strawweight unified champion
LAST FIGHT: W (UD10) Leonela Yudica, July 28
NEXT FIGHT: TBA
6. MIKAELA MAYER Previous ranking: No. 7
RECORD: 19-1, 5 KOs
DIVISION: Junior lightweight
LAST FIGHT: W (UD10) Silvia Bortot, Sept. 2
NEXT FIGHT: Jan. 20 vs. Natasha Jonas
7. SAVANNAH MARSHALL Previous ranking: No. 10
RECORD: 13-1, 10 KOs
DIVISION: Super middleweight undisputed champion
LAST FIGHT: W (MD10) Franchon Crews Dezurn, July 1
NEXT FIGHT: TBA
8. JESSICA MCCASKILL Previous ranking: No. 8
RECORD: 12-3-1, 5 KOs
DIVISION: Welterweight undisputed champion
LAST FIGHT: DRAW (SD10) Sandy Ryan, Sept. 23
NEXT FIGHT: TBA
9. NATASHA JONAS Previous ranking: N/R
RECORD: 14-2-1, 9 KOs
DIVISION: Welterweight champion
LAST FIGHT: W (TKO10) Kandi Wyatt, July 1
NEXT FIGHT: January 20 vs. Mikaela Mayer
10. DELFINE PERSOON Previous ranking: N/R
RECORD: 48-3, 19 KOs
DIVISION: Junior lightweight
LAST FIGHT: W (SD10) Bo Mi Re Shin, May 28
NEXT FIGHT: TBA
The formula
The rankings are based on a descending points system, with a first-place vote receiving 10 points, a second-place vote receiving nine points and so on.
Others receiving votes: Christina Hammer (3), Franchon Crews Dezurn (2), Jessica Nery Plata (2), Yokasta Valle (2), Terri Harper (1), Hyun Choi (1), Shadasia Green (1).
How our experts voted
Michael Rothstein: 1. Shields, 2. Cameron, 3. Taylor, 4. Serrano, 5. Estrada, 6. McCaskill, 7. Mayer, 8. Marshall, 9. Jonas, 10. Valle
Timothy Bradley Jr.: 1. Shields, 2. Taylor, 3. Serrano, 4. Estrada, 5. Mayer, 6. Cameron, 7. Marshall, 8. McCaskill, 9. Jonas, 10. Crews-Dezurn
Nick Parkinson: 1. Shields, 2. Taylor, 3. Serrano, 4. Cameron, 5. Estrada, 6. Mayer, 7. Jonas, 8. Marshall, 9. McCaskill, 10. Harper
Salvador Rodriguez: 1. Shields, 2. Serrano, 3. Taylor, 4. Cameron, 5. Estrada, 6. Mayer, 7. Marshall, 8. Jonas, 9. Nery Plata, 10. Valle
Bernardo Pilatti: 1. Shields, 2. Serrano, 3. Cameron, 4. Taylor, 5. Marshall, 6. McCaskill, 7. Jonas, 8. Estrada, 9. Mayer, 10. Crews-Dezurn
Charlie Moynihan: 1. Shield, 2. Serrano, 3. 3. Mayer, 4. Cameron, 5. Taylor, 6. Estrada, 7. Persoon, 8. Hammer, 9. Marshall, 10. Choi
Kel Dansby: 1. Shields, 2. Cameron, 3. Serrano, 4. Taylor, 5. McCaskill, 6. Marshall, 7. Estrada, 8. Mayer, 9. Jonas, 1p. Green
ESPN experts' poll
First place: Shields (7)
Second place: Serrano (3), Taylor (2), Cameron (2)
Third place: Serrano (3), Taylor (2), Mayer (1), Cameron (1)
Fourth place: Cameron (3), Taylor (2), Serrano (1), Estrada (1)
Fifth place: Estrada (3), Taylor (1), Mayer (1), Marshall (1), McCaskill (1)
Sixth place: Mayer (2), McCaskill (2), Cameron (1), Estrada (1), Marshall (1)
Seventh place: Marshall (2), Jonas (2), Estrada (1), Mayer (1), Persoon (1)
Eighth place: Marshall (2), Estrada (1), McCaskill (1), Mayer (1), Jonas (1), Hammer (1)
Ninth place: Jonas (3), Mayer (1), Marshall (1), McCaskill (1), Nery Plata (1)
10th place: Crews-Dezurn (2), Valle (2), Choi (1) Green (1), Harper (1)