Thailand champions Muang Thong United ended a six-game losing streak as they beat battling Chiang Rai United 4-2 in a vital Thai League (T1) clash on Friday evening.
And it was a fitting farewell to Chanathip Songkrasin as the Thailand international midfielder joins Consadole Sapporo in the J-League before the domestic season resumes for the start of the second leg on June 17.
Victory took the Thai champions back to the top of T1, level on points with Buriram United. But they will be relieved to have seen off the third-placed side as they were pushed all the way, and got the benefit of some controversial decisions.
The Kirins had been on a horror run, having been defeated just once in the previous 18 matches this year, including five matches in the AFC Champions League (ACL).
Following up such a prosperous period with six straight defeats has been painful. A potentially pivotal T1 match was the last thing they needed after a trip to Japan had resulted in Tuesday's 4-1 defeat to Kawasaki Frontale in the ACL.
The hosts came to life in the 14th minute when Tristan Do's surge towards the box was ended with a foul from Vander Luiz. Theerathon Bunmathan whipped in a free kick that goalkeeper Pattara Piyapatrakitti punched wide.
From Theerathon's corner, Celio Santos sent in a powerful header from close range, but Pattara tipped the ball over.
But it was third time lucky for the home side as Theerathon's corner was helped towards goal by Adisak Kraisorn and deflected into the net. Adisak tried to claim the goal, but it was Chiang Rai's Thithipan Puangchan and Suriya Singmui who appeared to get the decisive touches.
In response, Luiz struck a powerful effort from 30 yards out in the 25th minute, but Kawin Thamsatchanan watched the ball sail over.
This sparked a flurry of pressure from Chiang Rai and Celio looked lucky not to concede a penalty when he took down Rafael Coelho in the box.
But Muang Thong weathered the storm and went in two-up at half-time after a stunning strike from Theerathon.
The full-back played the ball inside to Chanathip Songkrasin, and the playmaker's return pass found him just inside the opposition area on the left. Theerathon cut inside two defenders before unleashing a right-footed drive high into the net from 20 yards out.
But the champions were back under pressure when Chiang Rai pulled a goal back five minutes after the break. Luiz broke free down the right and crossed for Rafael to tap into an empty net.
The hosts' vulnerability was demonstrated when Theerathon and Luiz saw red for an altercation. As Luiz tried to work his way past the full-back, Theerathon swung his arms as he blocked him off. Luiz reacted angrily and Theerathon pushed the Brazilian in the face before pushing his forehead into the Chiang Rai playmaker's face.
The referee sent both off, but Luiz was unlucky as Theerathon lost his head again.
Muang Thong took advantage of their reprieve by restoring their two-goal cushion in the 64th minute. Great work from Tristan Do set up the chance for substitute Ratchapol Nawanno to fire home from 16 yards.
Chiang Rai kept pushing and former Muang Thong midfielder Thitipan made it 3-2 with five minutes left when he hooked in a shot from close range.
But the hosts finally saw off their opponents in added time when Teerasil Dangda broke forward and played in Sanukran Thinjom to fire in number four.
Muang Thong United: Kawin Thamsatchanan; Tristan Do, Naoaki Aoyama, Celio Santos, Theerathon Bunmathan; Lee Ho, Wattana Playnum; Peerapat Notchaiya, Chanathip Songkrasin, Teerasil Dangda; Adisak Kraisorn.
Chiang Rai United: Pattara Piyapatrakitti; Piyaphon Phanichakul, Everton Goncalves, Shinnaphat Lee-Oh, Suriya Singmui; Thithipan Puangchan, Tanaboon Kesarat, Thossawat Limwannasathian; Vander Luiz, Felipe Azevedo, Rafael Coelho