The National Championship was the next stage from the regional stage of 2021–22 Thai League 3. The winners and runners-ups of each region would qualify for this round to find 3 clubs promoting to 2022–23 Thai League 2.
Teams
TeamQualifying methodUthai ThaniNorthern region championsPhitsanulokNorthern region runners-upMuang Loei UnitedNortheastern region championsSisaketNortheastern region runners-upPattaya Dolphins UnitedEastern region championsChachoengsao Hi-TekEastern region runners-upSaraburi UnitedWestern region championsPathumthani UniversityWestern region runners-upKrabiSouthern region championsNakhon Si UnitedSouthern region runners-upNorth Bangkok UniversityBangkok Metropolitan region championsBangkokBangkok Metropolitan region runners-up
Group stage Upper region
Lower region
Knockout stage Winners, runners-up, and third place of 2021–22 Thai League 3 would be promoted to the 2022–23 Thai League 2.
Third place play-off Summary
Matches
Nakhon Si United won 4–3 on aggregate.
Final Summary
Matches 1st leg
Lineups:GK 37 Worawut SukhunaCB 33 Júnior Lopes CB 19 Wattana PlaynumCB 43 Wanchat Choosong RM 91 Phongsakon TrisatCM 8 Narong Jansawek (c)CM 6 Watcharakorn Manoworn LM 95 Nattapong ChaideeRF 20 Chitpanya Tisud CF 11 Ricardo Santos LF 99 Chigozie Mbah Substitutes:GK 18 Boonyakait WongsajaemDF 3 Supoj WonghoiDF 17 Jakree Pankam MF 4 Peemwit ThongnitirojMF 7 Datsakorn ThonglaoMF 10 Phattharaphon Junsuwan MF 47 Kasidit Kalasin FW 9 Kirati KeawsombatFW 26 Nontapat NaksawatHead Coach: Therdsak Chaiman Lineups:GK 38 Wuttichai PanbootRB 11 Atthaphon Chongrak CB 5 Anuwat YungyuenCB 20 Seydou KonéLB 33 Kridsada LimseeputDM 14 Akarat Punkaew (c)RM 32 Phuchakhen ChandaengCM 22 Kroekpon Kaewmuean CM 4 Siwapong JarernsinLM 30 Romário Reginaldo Alves CF 99 Alexandre Balotelli Substitutes:GK 81 Chaiyapat HonbanlengDF 3 Suchart ChayyaiDF 18 Natthanon Charoensingkeewan DF 39 Khunnaphon UdomsinMF 6 Techin Mooktarakosa MF 8 Rattasart Makasoot MF 37 Kongpop ArtsermFW 9 Surin Ra-obFW 10 Arnon PetwatHead Coach: Prajak Weangsong
2nd leg
Lineups:GK 38 Wuttichai PanbootRB 11 Atthaphon Chongrak CB 5 Anuwat YungyuenCB 20 Seydou Koné LB 33 Kridsada Limseeput DM 14 Akarat Punkaew (c)CM 4 Siwapong Jarernsin CM 6 Techin Mooktarakosa RF 32 Phuchakhen Chandaeng CF 99 Alexandre BalotelliLF 30 Romário Reginaldo Alves Substitutes:GK 81 Chaiyapat HonbanlengDF 7 Aitipol KaewkeawDF 39 Khunnaphon UdomsinMF 8 Rattasart Makasoot MF 22 Kroekpon Kaewmuean MF 26 Kritsanapol Booncharee MF 37 Kongpop ArtsermFW 10 Arnon Petwat FW 59 Chudit Wanpraphao Head Coach: Prajak Weangsong Lineups:GK 37 Worawut SukhunaCB 33 Júnior Lopes CB 19 Wattana Playnum CB 43 Wanchat Choosong RM 91 Phongsakon TrisatCM 8 Narong Jansawek (c) CM 6 Watcharakorn ManowornLM 95 Nattapong ChaideeRF 23 Mongkol Tossakrai CF 11 Ricardo Santos LF 99 Chigozie Mbah Substitutes:GK 18 Boonyakait WongsajaemDF 3 Supoj WonghoiDF 17 Jakree PankamMF 4 Peemwit ThongnitirojMF 7 Datsakorn Thonglao MF 10 Phattharaphon Junsuwan MF 20 Chitpanya TisudMF 47 Kasidit KalasinFW 26 Nontapat Naksawat Head Coach: Therdsak Chaiman Uthai Thani won 3–1 on aggregate.
Statistics
Goalscorers
Teams promoted to 2022–23 Thai League 2 Uthai Thani (champions) Krabi (runners-up) Nakhon Si United (third-placed)
References