Uthai Kailas (), known professionally as Kangwannoi Or.Sribualoi (), is a Thai former professional Muay Thai fighter. He is a former Lumpinee Stadium Bantamweight Champion who was active during the 1980s and 1990s. He is also the older half-brother of Saenklai SitKruOd, another famous fighter.
He trained at the SitKruOd gym alongside his brother, Saenklai SitKruOd.
He fought during the Golden Era of Muay Thai against many notable fighters including Wangchannoi Sor.Palangchai, Boonlai Sor.Thanikul, Dokmaipa Por.Pongsawang, Rajasak Sor.Vorapin, Taweesaklek Ploysakda, Padejseuk Kiatsamran, Yodpetch Sor.Jitpattana, M16 Bor.Khor.Sor., and Nuengthoranee Petchyindee.
|- style="background:#fbb;" | 1995-03-25 || Loss||align=left| Chingchai Sakdarun || || Bangkok, Thailand || TKO || 5 ||
|- style="background:#cfc;" | 1994-12-06 || Win ||align=left| Kukrit Sor.Nayayarm || Lumpinee Stadium || Bangkok, Thailand || Decision || 5 || 3:00
|- style="background:#cfc;" | 1993-07-20 || Win ||align=left| M16 Bor.Khor.Sor. || Lumpinee Stadium || Bangkok, Thailand || Decision || 5 || 3:00
|- style="background:#cfc;" | 1993-06-22 || Win ||align=left| M16 Bor.Khor.Sor. || Lumpinee Stadium || Bangkok, Thailand || Decision || 5 || 3:00
|- style="background:#cfc;" | 1993-05-25 || Win||align=left| Saentor Kiatmuangkanchan || Lumpinee Stadium || Bangkok, Thailand || Decision || 5 || 3:00
|- style="background:#fbb;" | 1993-02-02 || Loss ||align=left| Padejseuk Kiatsamran || || Thailand || Decision || 5 || 3:00
|- style="background:#fbb;" | 1993-01-15 || Loss ||align=left| M16 Bor.Khor.Sor. || Lumpinee Stadium || Bangkok, Thailand || Decision || 5 || 3:00
|- style="background:#cfc;" | 1992-12-24 || Win ||align=left| Changnoi Sirimongkol || || Thailand || Decision || 5 || 3:00
|- style="background:#cfc;" | 1992-11-17 || Win ||align=left| Duangkaew Sor.Banmai || || Thailand || Decision || 5 || 3:00
|- style="background:#cfc;" | 1992-10-20 || Win ||align=left| Suwitlek Sor.Sakaowarat || Lumpinee Stadium || Bangkok, Thailand || Decision || 5 || 3:00
|- style="background:#cfc;" | 1992-10-06 || Win ||align=left| Nuengsiam Kiatwichian || Lumpinee Stadium || Bangkok, Thailand || Decision || 5 || 3:00
|- style="background:#cfc;" | 1992-08-28 || Win ||align=left| Changnoi Sirimongkol || || Thailand || Decision || 5 || 3:00
|- style="background:#fbb;" | 1992-08-04 || Loss ||align=left| Chamuekpet Chorchamuang || || Thailand || Decision || 5 || 3:00
|- style="background:#cfc;" | 1992-07-08 || Win ||align=left| Jack Kiatniwat || Rajadamnern Stadium || Bangkok, Thailand || Decision || 5 || 3:00
|- style="background:#cfc;" | 1992-06-19 || Win ||align=left| Rajasak Sor.Vorapin || Lumpinee Stadium || Bangkok, Thailand || Decision || 5 || 3:00
|- style="background:#fbb;" | 1992-05-12 || Loss ||align=left| Pepsi Biyapan || || Thailand || Decision || 5 || 3:00
|- style="background:#cfc;" | 1992-04-10 || Win ||align=left| Kukrit Sor.Nayayarm || || Thailand || Decision || 5 || 3:00
|- style="background:#c5d2ea;" | 1992-03-06 || Draw ||align=left| Kukrit Sor.Nayayarm || Lumpinee Stadium || Bangkok, Thailand || Decision || 5 || 3:00
|- style="background:#cfc;" | 1992-01-24 || Win ||align=left| Kukrit Sor.Nayayarm || Lumpinee Stadium || Bangkok, Thailand || Decision || 5 || 3:00
|- style="background:#cfc;" | 1992-01-03 || Win ||align=left| Wisanlek Lukbangplasoi || Lumpinee Stadium || Bangkok, Thailand || Decision || 5 || 3:00
|- style="background:#fbb;" | 1991-09-20 || Loss ||align=left| Noppadet Sor.Rewadee || || Thailand || Decision || 5 || 3:00
|- style="background:#fbb;" | 1991-08-23 || Loss ||align=left| Noppadet Sor.Rewadee || Lumpinee Stadium || Bangkok, Thailand || Decision || 5 || 3:00
|- style="background:#fbb;" | 1991-08-02 || Loss ||align=left| Kukrit Sor.Nayayarm || Lumpinee Stadium || Bangkok, Thailand || Decision || 5 || 3:00
|- style="background:#cfc;" | 1991-06-24 || Win ||align=left| Noppadet Sor.Rewadee || Rajadamnern Stadium || Bangkok, Thailand || Decision || 5 || 3:00
|- style="background:#cfc;" | 1991-05-24 || Win ||align=left| Grandprixnoi MuangChaiyapum || || Thailand || Decision || 5 || 3:00
|- style="background:#cfc;" | 1991-05-03 || Win ||align=left| Yodpetch Sor.Jitpattana || || Thailand || Decision || 5 || 3:00
|- style="background:#fbb;" | 1991-03-19 || Loss ||align=left| Yodpetch Sor.Jitpattana || Lumpinee Stadium || Bangkok, Thailand || Decision || 5 || 3:00
|- style="background:#cfc;" | 1991-02-08 || Win ||align=left| Decha Sitbanjong || Lumpinee Stadium || Bangkok, Thailand || Decision || 5 || 3:00
|- style="background:#fbb;" | 1991-01-18 || Loss ||align=left| Decha Sitbanjong || Lumpinee Stadium || Bangkok, Thailand || Decision || 5 || 3:00
|- style="background:#cfc;" | 1990-12-21 || Win||align=left| Kukrit Sor.Naiyaam|| Lumpinee Stadium || Bangkok, Thailand || Decision || 5 || 3:00
|- style="background:#fbb;" | 1990-10-19 || Loss ||align=left| Yodpetch Sor.Jitpattana || Lumpinee Stadium || Bangkok, Thailand || Decision || 5 || 3:00
|- style="background:#fbb;" | 1990-09-07 || Loss ||align=left| Taweesaklek Ploysakda || Lumpinee Stadium || Bangkok, Thailand || Decision || 5 || 3:00 |- ! style=background:white colspan=9 |
|- style="background:#fbb;" | 1990-07-24 || Loss ||align=left| Taweesaklek Ploysakda || Lumpinee Stadium || Bangkok, Thailand || Decision || 5 || 3:00 |- ! style=background:white colspan=9 |
|- style="background:#cfc;" | 1990-06-08 || Win ||align=left| Wangchannoi Sor.Palangchai || Lumpinee Stadium || Bangkok, Thailand || Decision || 5 || 3:00
|- style="background:#cfc;" | 1990-05-27 ||Win ||align=left| Michael Barb || || Phoenix, USA || KO || 2 ||
|- style="background:#cfc;" | 1990-05-11 || Win ||align=left| Yodpetch Sor.Jitpattana || Lumpinee Stadium || Bangkok, Thailand || Decision || 5 || 3:00 |- ! style=background:white colspan=9 |
|- style="background:#cfc;" | 1990-04-24 || Win ||align=left| Dokmaipa Por Pongsawang || Lumpinee Stadium || Bangkok, Thailand || Decision || 5 || 3:00
|- style="background:#cfc;" | 1990-03-23 || Win ||align=left| Grandprixnoi Muangchaiyaphum || Lumpinee Stadium || Bangkok, Thailand || Decision || 5 || 3:00
|- style="background:#cfc;" | 1990-03-02 || Win ||align=left| Boonlai Sor.Thanikul || Lumpinee Stadium || Bangkok, Thailand || Decision || 5 || 3:00
|- style="background:#fbb;" | 1990-02-06 || Loss ||align=left| Boonlai Sor.Thanikul || Lumpinee Stadium || Bangkok, Thailand || Decision || 5 || 3:00
|- style="background:#cfc;" | 1990-01-20 || Win ||align=left| Dokmaipa Por Pongsawang || Lumpinee Stadium || Bangkok, Thailand || Decision || 5 || 3:00
|- style="background:#cfc;" | 1989-12-26 || Win ||align=left| Noppadet Sor.Rewadee || Lumpinee Stadium || Bangkok, Thailand || Decision || 5 || 3:00
|- style="background:#cfc;" | 1989-12-08 || Win ||align=left| Saichon Pichitsuek || Lumpinee Stadium || Bangkok, Thailand || Decision || 5 || 3:00 |- ! style=background:white colspan=9 |
|- style="background:#cfc;" | 1989-10-17 || Win ||align=left| Detduang Por.Pongsawang || Lumpinee Stadium || Bangkok, Thailand || Decision || 5 || 3:00
|- style="background:#cfc;" | 1989-09-01 || Win ||align=left| Yodpetch Sor.Jitpattana || Lumpinee Stadium || Bangkok, Thailand || Decision || 5 || 3:00
|- style="background:#fbb;" | 1989-08-04 || Loss ||align=left| Saichon Pichitsuek || Petchyindee, Lumpinee Stadium || Bangkok, Thailand || Decision (Unanimous) || 5 || 3:00 |- ! style=background:white colspan=9 |
|- style="background:#cfc;" | 1989-06-30 || Win ||align=left| Yodpetch Sor.Jitpattana || || Thailand || Decision || 5 || 3:00
|- style="background:#cfc;" | 1989-06-10 || Win ||align=left| Ploysenae Sor.Bodin || || Bo Rai district, Thailand || Decision || 5 || 3:00
|- style="background:#c5d2ea;" | 1989-05-16 || Draw||align=left| Teeyai Piyaphan || || Thailand || Decision || 5 || 3:00
|- style="background:#fbb;" | 1989-04-23 || Loss ||align=left| Klairuangnoi Sit Banjong || Samrong Stadium || Samut Prakan, Thailand || Decision || 5 || 3:00
|- style="background:#cfc;" | 1989-04-21 || Win||align=left| Khempetch Kiatakorn|| || Thailand || KO || 3 ||
|- style="background:#cfc;" | 1989-03-26 || Win||align=left| Teeyai Piyaphan || Samrong Stadium || Samut Prakan, Thailand || Decision || 5 || 3:00
|- style="background:#cfc;" | 1989-02-26 || Win ||align=left| Payu Lukthapfa || Samrong Stadium || Samut Prakan, Thailand || Decision || 5 || 3:00
|- style="background:#fbb;" | 1989-01-27 || Loss||align=left| Teeyai Piyaphan || Lumpinee Stadium || Bangkok, Thailand || Decision || 5 || 3:00
|- style="background:#cfc;" | 1989-01-26 || Win ||align=left| Pansak Boonsomchai || || Buriram province, Thailand || Decision || 5 || 3:00
|- style="background:#cfc;" | 1989-01-16 || Win ||align=left| Saengdaonoi Tor.Silachai || || Dan Khun Thot district, Thailand || Decision || 5 || 3:00
|- style="background:#cfc;" | 1988-12-22 || Win ||align=left| Namphon Chomphuthong || Nok Khao Stadium || Pattaya, Thailand || Decision || 5 || 3:00
|- style="background:#fbb;" | 1987-01-10 || Loss ||align=left| Nuengthoranee Petchyindee || Lumpinee Stadium || Bangkok, Thailand || referee stoppage || 4 ||
|- | colspan=9 | Legend: