Claressa Shields is back on top in the ESPN women's pound-for-pound rankings after a dominant victory over Savannah Marshall. With the victory, Shields (13-0, 2 KOs), became the undisputed middleweight champion for the second time. She is the first fighter, male or female, to be undisputed in the same division twice. She's also a former undisputed junior middleweight champion.
"The line between Shields and Katie Taylor is so incredibly close and it's a shame the difference in weight classes means the two would never be able to fight," ESPN boxing writer Michael Rothstein said. "I moved Shields above Taylor because what I had been waiting for from Shields is this type of high-level fight.
"That's not her fault, it's the reality of the divisions she is fighting in. But how she fought, and how she beat, another top 10 fighter in Marshall just showed how good Shields really is."
While Shields has been in this spot before, a new woman is joining the rankings for the first time. Alycia Baumgardner is making her debut after defeating Mikaela Mayer on Saturday. Baumgardner (13-1, 7 KOs) added the WBO and IBF women's junior lightweight titles to her WBC with an impressive split-decision win over Mayer. The victory puts her at No. 5, dropping Mayer one spot to No. 6.
Here's the current top 10.
Note: Results are through Oct. 18.
1. CLARESSA SHIELDS 
Previous ranking: No. 2
RECORD: 13-0, 2 KOs
DIVISION: Middleweight undisputed champion
LAST FIGHT: W (UD10) Savannah Marshall, Oct. 15
NEXT FIGHT: TBA
2. KATIE TAYLOR 
Previous ranking: No. 1
RECORD: 21-0, 6 KOs
DIVISION: Lightweight undisputed champion
LAST FIGHT: W (SD10) Amanda Serrano, April 30
NEXT FIGHT: Oct. 29 vs. Karen Elizabeth Carabajal
3. AMANDA SERRANO 
Previous ranking: No. 3
RECORD: 42-2-1, 30 KOs
DIVISION: Featherweight unified champion
LAST FIGHT: W (UD10) Sarah Mahfoud, Sept. 24
NEXT FIGHT: TBA
4. JESSICA MCCASKILL Previous ranking: No. 4
RECORD: 12-2, 5 KOs
DIVISION: Welterweight undisputed champion
LAST FIGHT: W (TKO3) Alma Ibarra, June 25
NEXT FIGHT: Nov. 5 vs. Chantelle Cameron
5. ALYCIA BAUMGARDNER Previous ranking: N/R
RECORD: 13-1, 7 KOs
DIVISION: Junior lightweight unified champion
LAST FIGHT: W (SD10) Mikaela Mayer, Oct. 15
NEXT FIGHT: TBA
6. MIKAELA MAYER Previous ranking: No. 5
RECORD: 17-1, 5 KOs
DIVISION: Junior lightweight
LAST FIGHT: L (SD10) Alycia Baumgardner, Oct. 15
NEXT FIGHT: TBA
7. SENIESA ESTRADA Previous ranking: 6
RECORD: 23-0, 9 KOs
DIVISION: Strawweight champion
LAST FIGHT: W (UD10) Jazmin Gala Villarino, Nov. 12
NEXT FIGHT: TBA
8. FRANCHON CREWS-DEZURN Previous ranking: 9
RECORD: 8-1, 2 KOs
DIVISION: Super middleweight undisputed champion
LAST FIGHT: W (UD10) Elin Cederroos, April 30
NEXT FIGHT: TBA
9. DELFINE PERSOON Previous ranking: No. 8
RECORD: 47-3, 19 KOs
DIVISION: Lightweight
LAST FIGHT: W (UD10) Elhem Mekhaled, May 14
NEXT FIGHT: TBA
T-10. SAVANNAH MARSHALL Previous ranking: 7
RECORD: 12-1, 5 KOs
DIVISION: Middleweight
LAST FIGHT: L (UD10) Claressa Shields, Oct. 15
NEXT FIGHT: TBA
T-10. CHANTELLE CAMERON Previous ranking: 10
RECORD: 16-0, 8 KOs
DIVISION: Junior welterweight unified champion
LAST FIGHT: W (UD10) Victoria Noelia Bustos, May 21
NEXT FIGHT: Nov. 5 vs. Jessica McCaskill
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 (7), Natasha Jonas (5), Terri Harper (5), Kali Reis (4), Hyun Choi (1).
How our experts voted
Michael Rothstein: 1. Shields, 2. Taylor, 3. Serrano, 4. McCaskill, 5. Estrada, 6. Baumgardner, 7. Mayer, 8. Persoon, 9. Cameron, 10. Marshall
Nick Parkinson: 1. Taylor, 2. Serrano, 3. Shields, 4. McCaskill, 5. Baumgardner, 6. Marshall, 7. Mayer, 8. Estrada, 9. Harper, 10. Cameron
Michelle Joy Phelps: 1. Shields, 2. Taylor, 3. Serrano, 4. McCaskill, 5. Crews-Dezurn, 6. Cameron, 7. Reis, 8. Jonas, 9. Baumgardner, 10. Mayer
Salvador Rodriguez: 1. Shields, 2. Taylor, 3. Serrano, 4. McCaskill, 5. Baumgardner, 6. Crews-Dezurn, 7. Estrada, 8. Mayer, 9. Jonas, 10. Harper
Bernardo Pilatti: 1. Shields, 2. Taylor, 3. Serrano, 4. McCaskill, 5. Baumgardner, 6. Mayer, 7. Persoon, 8. Estrada, 9. Marshall, 10. Cameron
Charlie Moynihan: 1. Taylor, 2. Shields, 3. Serrano, 4. McCaskill, 5. Baumgardner, 6. Mayer, 7. Persoon, 8. Hammer, 9. Estrada, 10. Choi
Kel Dansby: 1. Shields, 2. Taylor, 3. McCaskill, 4. Serrano, 5. Bumgarnder, 6. Crews-Dezurn, 7. Estrada, 8. Mayer, 9. Harper, 10. Marshall
ESPN experts' poll
First place: Shields (5), Taylor (2)
Second place: Taylor (5), Shields (1), Serrano (1)
Third place: Serrano (5), Shields (1), McCaskill (1)
Fourth place: McCaskill (6), Serrano (1)
Fifth place: Baumgardner (5), Estrada (1), Crews-Dezurn (1)
Sixth place: Mayer (2), Crews-Dezurn (2), Baumgardner (1), Marshall (1), Cameron (1)
Seventh place: Mayer (2), Estrada (2), Persoon (2), Reis (1)
Eighth place: Mayer (2), Estrada (2), Persoon (1), Jonas (1), Hammer (1)
Ninth place: Harper (2), Baumgardner (1), Estrada (1), Marshall (1), Cameron (1), Jonas (1)
10th place: Marshall (2), Cameron (2), Mayer (1), Harper (1), Choi (1)