He won the 2010 IBSF World Snooker Championship in Damascus, Syria, defeating India's Pankaj Advani 10–7 in the final. This earned him a place on the professional Main Tour for the 2011/2012 season.
Due to being a new player on the tour and therefore unranked he would need to win four qualifying matches to reach the ranking event main draws. He came closest to doing this in the World Open when he beat Andrew Pagett and Liu Song, before losing to Michael Holt 4–5.
Poomjaeng played all 12 of the minor-ranking Players Tour Championship events throughout the season, with his best finish coming in Event 8 where he beat seven-time world champion Stephen Hendry and Stephen Maguire to reach the last 16, but succumbed 1–4 to Ben Woollaston. Poomjaeng finished the season ranked world number 82, comfortably outside the top 64 who retain their places for the 2012/2013 season. However, his final placing of 57th on the PTC Order of Merit was good enough to earn him a spot for next season.
The 2012/2013 season saw Poomjaeng qualify for the main draw of a ranking event for the first time. This came in the 2013 German Masters, by defeating Yu Delu and Fergal O'Brien. He lost 2–5 to Barry Hawkins in the first round in Berlin. Poomjaeng continued his form by winning four matches to reach the China Open. Once at the venue in Beijing, he saw off Zhu Yinghui 5–2 in the wildcard round, but then lost 3–5 to Mark Davis in the first round. In the Players Tour Championship events this season Poomjaeng's best results were last 16 defeats in the First and Fourth events, losing to Alan McManus and Mark Joyce respectively. He was ranked 42nd on the PTC Order of Merit. Poomjaeng beat Michael Leslie 10–4, Liu Chuang 10–9, Anthony Hamilton 10–4 and Jamie Cope 10–3 to qualify for the World Championship for the first time. He faced sixth seed Stephen Maguire in the first round and produced a huge shock with the world number 70 Poomjaeng winning 10–9, with a composed 63 break in the final frame. The crowd warmed to Poomjaeng as he walked to the wrong table at the start of play and animatedly expressed his emotions throughout the match, including applauding his own safety shot. He played Michael White in the second round and lost the fourth frame without a ball having been potted due to missing the reds three times. The rules of snooker state that if a red can be seen full ball and is missed on three consecutive shots, the frame is conceded. Poomjaeng lost the session 1–7 and went on to be defeated 3–13. His cheque of £16,000 for reaching the last 16 more than doubled his previous career earnings since turning professional in 2011. Poomjaeng finished the season ranked world number 67.
In his opening match of the season, Poomjaeng defeated Darren Cook 5–1 to qualify for the 2013 Wuxi Classic in China where he beat Dominic Dale 5–1 in the first round, before losing by a reverse of this scoreline to John Higgins. Poomjaeng then won three matches to qualify for the Australian Goldfields Open, but lost 5–1 to Barry Hawkins in the first round. Poomjaeng won the bronze medal at the World Games thanks to a 3–2 victory over Brazil's Igor Figueiredo. He lost in the last 32 of the Indian Open to Liang Wenbo and at the UK Championship, lost 6–0 in the second round to world number four Judd Trump, having defeated fellow Thai player Thepchaiya Un-Nooh 6–5 in the opening round. Poomjaeng eliminated defending champion Ali Carter 5–4 in the opening round of the German Masters, after having trailed 4–2, but was then beaten in a deciding frame by Xiao Guodong in the second round. His fourth exit in the last 32 of a ranking event this season came at the China Open as Shaun Murphy whitewashed him 5–0. Poomjaeng saw off Zhang Anda and Craig Steadman to stand one match away from playing in the World Championship for the second year in a row, but from 4–2 ahead he lost eight of the last nine frames against 1997 champion Ken Doherty to miss out. He rose 20 spots to be ranked world number 47 at the end of the season.
At the Paul Hunter Classic, Poomjaeng won three matches and then defeated Neil Robertson 4–2 to reach the quarter-finals where he lost 4–2 to Rod Lawler. This result would later help him finish 32nd on the Order of Merit. Poomjaeng's first appearance at a ranking event this season was at the International Championship, but he was beaten 6–2 by Mark Davis in the first round. At the UK Championship he recorded wins over Andrew Norman and Michael Holt, before Marco Fu knocked him out 6–3 in the third round. Fu also eliminated Poomjaeng in the second round of the Welsh Open this time 4–2. Poomjaeng won three frames in a row from 3–1 down against Robertson in the first round of the China Open with the match eventually going into a deciding frame. Poomjaeng took it on the final black and then whitewashed Jack Lisowski 5–0 to play in the last 16 of a ranking event for the only time this season, where he lost 5–1 against Gary Wilson.
Poomjaeng was narrowly beaten 6–5 by Michael White in the first round of the International Championship. He defeated Chris Melling 6–4 and Ryan Day 6–2 at the UK Championship and recovered from 5–0 down against Mark Joyce to win 6–5 and reach the fourth round. He potted just 13 points in the first five frames against Mark Selby and there was no comeback this time as he lost 6–1. A pair of 4–1 victories over Craig Steadman and Robert Milkins saw Poomjaeng reach the third round of the Welsh Open, where he was beaten 4–3 by Yu Delu. Poomjaeng lost 5–4 to Ryan Day in the first round of the China Open, but saw off Eden Sharav 10–4 and Robin Hull 10–5 to reach the final qualifying round for the World Championship. He fell just short of playing at the Crucible again as he lost 10–9 to Mitchell Mann.
Poomjaeng had an extremely poor 2016/2017 season. He did not get past the last 64 of a single event and was on a losing run of 11 matches until he beat Chen Zhe 10–7 in World Championship qualifying. Poomjaeng lost 10–4 to Graeme Dott in the next round and finished 70th in the rankings having started the season 45th. He did not enter Q School and has therefore been relegated from the snooker tour.
Poomjaeng is based in the Star Academy in Sheffield and shares a house with four other Thai players, including former world number three and professional since 1989, James Wattana, whom Poomjaeng has described as a big brother. His real elder brother is Suchakree "Kwan" Poomjaeng, who has played on the professional snooker tour in the past. He is married to Korawan and has a daughter called Gim Gim.