Rangsan Viwatchaichok

Rangsan Viwatchaichok (รังสรรค์ วิวัฒน์ชัยโชค; ), born January 22, 1979), simply known as Aon (อ้น; ) is a Thai professional football manager and former player who is the head coach of Thai League 1 club Port.

Rangsan currently holds the record for the all-time most appearance in Thai League 1 with 439 appearances.

Rangsan is known for his set pieces freekick back in his playing career.

Club career
Rangsan is a Thai retired professional footballer who plays as a defensive midfielder or a left back. He previously played for four other club teams in Thailand and Singapore with Geylang United.

International career
Rangsan has currently played 29 times for the senior Thailand national team, and he has scored one goal in the process.

BEC Tero Sasana
On 11 July 2013, BEC Tero Sasana sacked René Desaeyere and promoted Choketawee Promrut to be the club interim manager. Rangsan, who was the club captain, was also promoted to be the assistant coach.

On 9 August 2015, Rangsan was promoted to be the interim manager of BEC Tero Sasana after the removal of Kenny Shiels.

He had coached the club for three games before the appointment of Manuel Cajuda on 27 August.

On 1 December 2015, he was promoted to be the interim manager again after the resignation of Manuel Cajuda. Rangsan managed the club in the last three games of 2015 season with the record of 2 wins and 1 loss. The club set to relegate to Division 1 according to the final standing but still remained in top league after the withdraw of Saraburi from the competition.

Suphanburi
On 17 April 2017, Rangsan was appointed as assistant manager of Suphanburi under manager Adebayo Gbadebo.

Police Tero
On 23 April 2018, FOX Sports Asia reported in an article that Rangsan was appointed head coach of Police Tero following the departure of Englishman Scott Cooper. On 29 June, he was demoted to assistant under Totchawan Sripan before getting promoted to manager again on 14 September the same year.

Port
After 5 years at Police Tero, Rangsan was appointed to replace Surapong Kongthep as the manager of Thai League 1 club Port on 8 November 2023.

Player

 * BEC Tero Sasana
 * Thai Premier League: 2000
 * Thai League Cup: 2014


 * Krung Thai Bank
 * Thai Premier League: 2002–03, 2003–04


 * Buriram United
 * Thai Premier League: 2008, 2011
 * Thai FA Cup: 2011
 * Thai League Cup: 2011

Manager

 * Police Tero
 * Thai League 2 runner-up: 2019

Individual
 * Thai League 1 Coach of the Month: October 2022, December 2023