# 2021 Cary Challenger II – Singles

Mitchell Krueger was the defending champion and successfully defended his title.
Krueger won the title after defeating Bjorn Fratangelo 6–4, 6–3 in the final.

## Seeds

* Tennys Sandgren (first round, defaulted)
* Denis Kudla (semifinals)
* Salvatore Caruso (second round)
* Alex Bolt (first round)
* Jason Jung (first round)
* Mitchell Krueger (champion)
* Michael Mmoh (quarterfinals)
* Bjorn Fratangelo (final)

## 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 | 6$^2$ | 7$^7$ | 6 | | | | |
| | Aleksandar Vukic | 7$^7$ | 6$^4$ | 2 | | | | |
| | Aleksandar Vukic | 7$^7$ | 6$^4$ | 2 | 8 | Bjorn Fratangelo | 4 | 3 |
| | | | | | 6 | Mitchell Krueger | 6 | 6 |
| 6 | Mitchell Krueger | 6 | 3 | 7$^7$ | 6 | Mitchell Krueger | 6 | 6 |
| 2 | Denis Kudla | 2 | 6 | 6$^2$ | | | | |

### 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 | Quarterfinals | Semifinals | Semifinals | Semifinals | Semifinals | Semifinals |
| 1 | T Sandgren | 1$^d$ | | | | | | | | | | | | | | | | | |
| | C Eubanks | 0 | | | | C Eubanks | 6 | 6$^6$ | 4 | | | | | | | | | | |
| | R Peniston | 6 | 6 | | | R Peniston | 4 | 7$^8$ | 6 | | | | | | | | | | |
| | P Polansky | 3 | 2 | | | | | | | | R Peniston | 3 | 5 | | | | | | |
| | U Blanch | 5 | 0 | | | | | | | 8 | B Fratangelo | 6 | 7 | | | | | | |
| Q | S Mochizuki | 7 | 6 | | Q | S Mochizuki | 2 | 1 | | | | | | | | | | | |
| Q | A Sarkissian | 2 | 7 | 1 | 8 | B Fratangelo | 6 | 6 | | | | | | | | | | | |
| 8 | B Fratangelo | 6 | 5 | 6 | | | | | | | | | | | 8 | B Fratangelo | 6$^2$ | 7$^7$ | 6 |
| 3 | S Caruso | 6 | 6 | | | | | | | | | | | | | A Vukic | 7$^7$ | 6$^4$ | 2 |
| | C Harrison | 3 | 3 | | 3 | S Caruso | 2 | 4 | | | | | | | | | | | |
| | Mi Redlicki | 4 | 4 | | | A Vukic | 6 | 6 | | | | | | | | | | | |
| | A Vukic | 6 | 6 | | | | | | | | A Vukic | 3 | 6 | 6 | | | | | |
| | S Kozlov | 5 | 0$^r$ | | | | | | | WC | Z Svajda | 6 | 2 | 3 | | | | | |
| WC | Z Svajda | 7 | 2 | | WC | Z Svajda | 7 | 6 | | | | | | | | | | | |
| Q | R Hijikata | 6 | 6 | | Q | R Hijikata | 5 | 3 | | | | | | | | | | | |
| 5 | J Jung | 4 | 4 | | | | | | | | | | | | | | | | |

### 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 | Semifinals | Semifinals | Semifinals | Semifinals | Semifinals |
| 6 | M Krueger | 6 | 6 | | | | | | | | | | | | | | | |
| | J Kubler | 3 | 2 | | 6 | M Krueger | 6 | 6 | | | | | | | | | | |
| | N Mejía | 4 | 4 | | | D Kelly | 4 | 4 | | | | | | | | | | |
| | D Kelly | 6 | 6 | | | | | | | 6 | M Krueger | 6 | 6 | | | | | |
| | JC Aragone | 3 | 6 | 6 | | | | | | | M Purcell | 3 | 2 | | | | | |
| | M Torpegaard | 6 | 2 | 3 | | JC Aragone | 2 | 2 | | | | | | | | | | |
| | M Purcell | 6 | 6 | | | M Purcell | 6 | 6 | | | | | | | | | | |
| 4 | A Bolt | 4 | 1 | | | | | | | | | | | 6 | M Krueger | 6 | 3 | 7$^7$ |
| 7 | M Mmoh | 6 | 6 | | | | | | | | | | | 2 | D Kudla | 2 | 6 | 6$^2$ |
| | N Rubin | 1 | 3 | | 7 | M Mmoh | 6 | 6 | | | | | | | | | | |
| WC | Luca Stäheli | 3 | 7 | 1 | | M Sasikumar | 4 | 4 | | | | | | | | | | |
| | M Sasikumar | 6 | 5 | 6 | | | | | | 7 | M Mmoh | 6$^3$ | 3 | | | | | |
| Q | A Kovacevic | 7$^7$ | 6 | | | | | | | 2 | D Kudla | 7$^7$ | 6 | | | | | |
| WC | Garrett Johns | 6$^3$ | 4 | | Q | A Kovacevic | 7$^7$ | 2 | 3 | | | | | | | | | |
| | D Young | 6$^3$ | 6 | 2 | 2 | D Kudla | 6$^2$ | 6 | 6 | | | | | | | | | |
| 2 | D Kudla | 7$^7$ | 4 | 6 | | | | | | | | | | | | | | |