title: 2018 Oracle Challenger Series – Chicago – Men's singles
text: # 2018 Oracle Challenger Series – Chicago – Men's singles
  
  This was the first edition of the tournament.
  
  Denis Istomin won the title after defeating Reilly Opelka 6–4, 6–2 in the final.
  
  ## Seeds
  
  * Andreas Seppi (first round)
  * Denis Istomin (champion)
  * Vasek Pospisil (first round)
  * Viktor Troicki (first round)
  * Michael Mmoh (second round)
  * Ruben Bemelmans (quarterfinals)
  * Elias Ymer (first round)
  * Noah Rubin (quarterfinals)
  
  ## 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 | Final | Final | Final | Final |
  | - | - | - | - | - | - | - | - |
  | Alt | Dominik Köpfer | 3 | $6^3$ | | | | |
  | | Reilly Opelka | 6 | $7^7$ | | | | |
  | | Reilly Opelka | 6 | $7^7$ | | Reilly Opelka | 4 | 2 |
  | | | | | 2 | Denis Istomin | 6 | 6 |
  | | Bjorn Fratangelo | 1 | 2 | 2 | Denis Istomin | 6 | 6 |
  | 2 | Denis Istomin | 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 | Quarterfinals | Semifinals | Semifinals | Semifinals | Semifinals |
  | - | - | - | - | - | - | - | - | - | - | - | - | - | - | - | - | - | - | - |
  | 1/WC | A Seppi | 3 | $6^5$ | | | | | | | | | | | | | | | |
  | Q | A Sarkissian | 6 | $7^7$ | | Q | A Sarkissian | 6 | $6^4$ | $6^3$ | | | | | | | | | |
  | | DE Galán | $6^5$ | 3 | | | JC Aragone | 2 | $7^7$ | $7^7$ | | | | | | | | | |
  | | JC Aragone | $7^7$ | 6 | | | | | | | | JC Aragone | 4 | 2 | | | | | |
  | Alt | D Köpfer | 6 | 6 | | | | | | | Alt | D Köpfer | 6 | 6 | | | | | |
  | Q | V Millot | 3 | 4 | | Alt | D Köpfer | 4 | $7^7$ | 6 | | | | | | | | | |
  | | M Krueger | 3 | 6 | 6 | | M Krueger | 6 | $6^4$ | 2 | | | | | | | | | |
  | 7 | E Ymer | 6 | 3 | 2 | | | | | | | | | | | Alt | D Köpfer | 3 | $6^3$ |
  | 3 | V Pospisil | 2 | 2 | | | | | | | | | | | | | R Opelka | 6 | $7^7$ |
  | Alt | D Young | 6 | 6 | | Alt | D Young | 6 | 6 | | | | | | | | | | |
  | | J-P Smith | 2 | 6 | 6 | | J-P Smith | 3 | 4 | | | | | | | | | | |
  | Alt | R Cid Subervi | 6 | 1 | 4 | | | | | | Alt | D Young | 6 | 2 | $6^5$ | | | | |
  | | R Quiroz | 3 | 2 | | | | | | | | R Opelka | 3 | 6 | $7^7$ | | | | |
  | | R Opelka | 6 | 6 | | | R Opelka | 6 | 6 | | | | | | | | | | |
  | | C Eubanks | 7 | 4 | 4 | 5 | M Mmoh | 4 | 4 | | | | | | | | | | |
  | 5 | M Mmoh | 5 | 6 | 6 | | | | | | | | | | | | | | |
  
  ### 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 |
  | - | - | - | - | - | - | - | - | - | - | - | - | - | - | - | - | - | - |
  | 8 | N Rubin | 6 | 3 | 6 | | | | | | | | | | | | | |
  | | E King | 4 | 6 | 3 | 8 | N Rubin | 5 | 6 | 7 | | | | | | | | |
  | | A Popyrin | 6 | 7 | | | A Popyrin | 7 | 2 | 5 | | | | | | | | |
  | | V Estrella Burgos | 3 | 5 | | | | | | | 8 | N Rubin | 1 | 4 | | | | |
  | Alt | E Escobedo | $6^3$ | 6 | 1 | | | | | | | B Fratangelo | 6 | 6 | | | | |
  | Q | S Bangoura | $7^7$ | 4 | 6 | Q | S Bangoura | 4 | 6 | 5 | | | | | | | | |
  | | B Fratangelo | 2 | 6 | 6 | | B Fratangelo | 6 | 1 | 7 | | | | | | | | |
  | 4 | V Troicki | 6 | 2 | 0 | | | | | | | | | | | B Fratangelo | 1 | 2 |
  | 6 | R Bemelmans | 7 | $7^8$ | | | | | | | | | | | 2 | D Istomin | 6 | 6 |
  | Q | H Nys | 5 | $6^6$ | | 6 | R Bemelmans | 6 | 6 | | | | | | | | | |
  | LL | K Uchida | 6 | 6 | | LL | K Uchida | 3 | 4 | | | | | | | | | |
  | WC | T-S Kwiatkowski | 1 | 3 | | | | | | | 6 | R Bemelmans | 3 | 4 | | | | |
  | WC | T Paul | 6 | 6 | | | | | | | 2 | D Istomin | 6 | 6 | | | | |
  | LL | R Roelofse | 3 | 2 | | WC | T Paul | 5 | 3 | | | | | | | | | |
  | | M Arévalo | 4 | 1 | | 2 | D Istomin | 7 | 6 | | | | | | | | | |
  | 2 | D Istomin | 6 | 6 | | | | | | | | | | | | | | |
  