title: 2021 Knoxville Challenger – Singles
text: # 2021 Knoxville Challenger – Singles
  
  Michael Mmoh was the defending champion but lost in the semifinals to Daniel Altmaier.
  
  Christopher Eubanks won the title after defeating Altmaier 6–3, 6–4 in the final.
  
  ## Seeds
  
  * Tennys Sandgren (first round)
  * Daniel Altmaier (final)
  * Vasek Pospisil (first round)
  * Mitchell Krueger (second round)
  * Jack Sock (quarterfinals)
  * J. J. Wolf (first round)
  * Dmitry Popko (first round)
  * Bjorn Fratangelo (semifinals)
  
  ## Draw
  
  ### Key
  
  * Q = Qualifier
  * WC = Wild card
  * LL = Lucky loser
  * Alt = Alternate
  * SE = Special exempt
  * PR = Protected ranking
  * ITF = ITF entry
  * JE = Junior exempt
  * w/o = Walkover
  * r = Retired
  * d = Defaulted
  * SR = Special ranking
  
  ### Finals
  
  | Semifinals | Semifinals | Semifinals | Semifinals | Semifinals | Final | Final | Final | Final |
  | - | - | - | - | - | - | - | - | - |
  | 8 | Bjorn Fratangelo | 5 | 5 | | | | | |
  | | Christopher Eubanks | 7 | 7 | | | | | |
  | | Christopher Eubanks | 7 | 7 | | | Christopher Eubanks | 6 | 6 |
  | | | | | | 2 | Daniel Altmaier | 3 | 4 |
  | | Michael Mmoh | 6 | 3 | 4 | 2 | Daniel Altmaier | 3 | 4 |
  | 2 | Daniel Altmaier | 3 | 6 | 6 | | | | |
  
  ### Top half
  
  | First round | First round | First round | First round | First round | Second round | Second round | Second round | Second round | Second round | Quarterfinals | Quarterfinals | Quarterfinals | Quarterfinals | Semifinals | Semifinals | Semifinals | Semifinals |
  | - | - | - | - | - | - | - | - | - | - | - | - | - | - | - | - | - | - |
  | 1 | T Sandgren | 6 | $6^3$ | $6^4$ | | | | | | | | | | | | | |
  | Alt | P Polansky | 3 | $7^7$ | $7^7$ | Alt | P Polansky | 6 | $6^2$ | $0^r$ | | | | | | | | |
  | WC | Em Nava | 6 | 6 | | WC | Em Nava | 2 | $7^7$ | 0 | | | | | | | | |
  | Q | D Young | 3 | 2 | | | | | | | WC | Em Nava | 4 | 4 | | | | |
  | Q | G Brouwer | 5 | 6 | 7 | | | | | | 8 | B Fratangelo | 6 | 6 | | | | |
  | Q | JC Aragone | 7 | 2 | 5 | Q | G Brouwer | 3 | 6 | 3 | | | | | | | | |
  | | Yo Watanuki | 4 | $6^5$ | | 8 | B Fratangelo | 6 | 3 | 6 | | | | | | | | |
  | 8 | B Fratangelo | 6 | $7^7$ | | | | | | | | | | | 8 | B Fratangelo | 5 | 5 |
  | 3 | V Pospisil | 6 | 2 | 3 | | | | | | | | | | | C Eubanks | 7 | 7 |
  | | C Eubanks | 2 | 6 | 6 | | C Eubanks | 6 | 2 | $7^7$ | | | | | | | | |
  | | G Soeda | 6 | $7^8$ | | | G Soeda | 3 | 6 | $6^4$ | | | | | | | | |
  | Alt | M Jaziri | 4 | $6^6$ | | | | | | | | C Eubanks | 6 | $7^{11}$ | | | | |
  | | J Jung | 6 | 6 | | | | | | | Alt | C Harrison | 3 | $6^9$ | | | | |
  | | J Kubler | 4 | 1 | | | J Jung | 6 | $6^3$ | $2^r$ | | | | | | | | |
  | Alt | C Harrison | 6 | 6 | | Alt | C Harrison | 3 | $7^7$ | 4 | | | | | | | | |
  | 6 | J. J. Wolf | 2 | 3 | | | | | | | | | | | | | | |
  
  ### Bottom half
  
  | First round | First round | First round | First round | First round | Second round | Second round | Second round | Second round | Second round | Quarterfinals | Quarterfinals | Quarterfinals | Quarterfinals | Quarterfinals | Semifinals | Semifinals | Semifinals | Semifinals | Semifinals |
  | - | - | - | - | - | - | - | - | - | - | - | - | - | - | - | - | - | - | - | - |
  | 7 | D Popko | 4 | 5 | | | | | | | | | | | | | | | | |
  | Q | A McHugh | 6 | 7 | | Q | A McHugh | 6 | 6 | | | | | | | | | | | |
  | | A Vukic | 3 | 6 | 5 | | S Kozlov | 4 | 4 | | | | | | | | | | | |
  | | S Kozlov | 6 | 4 | 7 | | | | | | Q | A McHugh | 6 | 3 | 1 | | | | | |
  | | Y Uchiyama | 5 | 3 | | | | | | | | M Mmoh | 3 | 6 | 6 | | | | | |
  | | M Mmoh | 7 | 6 | | | M Mmoh | $7^7$ | 1 | 6 | | | | | | | | | | |
  | PR | T Ito | $6^4$ | 3 | | 4 | M Krueger | $6^4$ | 6 | 2 | | | | | | | | | | |
  | 4 | M Krueger | $7^7$ | 6 | | | | | | | | | | | | | M Mmoh | 6 | 3 | 4 |
  | 5 | J Sock | $7^7$ | 7 | | | | | | | | | | | | 2 | D Altmaier | 3 | 6 | 6 |
  | WC | A Kovacevic | $6^4$ | 5 | | 5 | J Sock | 6 | $7^7$ | | | | | | | | | | | |
  | | P Gunneswaran | 6 | $7^7$ | | | P Gunneswaran | 3 | $6^1$ | | | | | | | | | | | |
  | | M Torpegaard | 2 | $6^2$ | | | | | | | 5 | J Sock | 6 | 5 | $6^2$ | | | | | |
  | | B Rola | 6 | $7^7$ | | | | | | | 2 | D Altmaier | 3 | 7 | $7^7$ | | | | | |
  | | T-S Kwiatkowski | 3 | $6^5$ | | | B Rola | $6^3$ | 4 | | | | | | | | | | | |
  | WC | A Walton | 3 | 2 | | 2 | D Altmaier | $7^7$ | 6 | | | | | | | | | | | |
  | 2 | D Altmaier | 6 | 6 | | | | | | | | | | | | | | | | |
  