After a goalless first-half, Thailand took a 70th minute lead when second-half substitute Pipat side-footed home Teerathep Winothai’s cross from close range before rifling in the second after collecting Teerathep’s header for a victory which was a reversal of the score line when the two met at the previous tournament in China.

Thailand coach Chanvit Polchovin and his counterpart Gabriel Calderon both made one change from the sides that started their respective 1-1 draws in the opening round of fixtures.

Jetsada Jitsawad failed to recover from a thigh muscle strain and the Bangkok University stopper’s place in the Thai defence was taken by 21-year-old Kiatprawut Saiwaeo, while Fawzi Basheer, who impressed in the last 30 minutes against Australia, earned a place in the starting 11 at the expense of Yousuf Al Busaidi.

The opening five minutes were played at a brisk tempo and while the Thais had the majority of possession it was the visitors who had the first half-chance of the game when keeper Kosin Hatthairattanakool safely gathered Ismail Al Ajmi’s cross-shot from the left.

Some Thai trickery in and around the penalty area almost saw the home side take a 20th minute lead but veteran striker Kiatisuk Senamuang couldn’t connect with Sutee Suksomkit’s pass across the face of goal.

Five minutes later Therdsak Chaiman got his shaven head on the end of Datsakorn Thonglao’s lofted pass but the diminutive Singapore Armed Forces playmaker was off target with his effort.

Ten minutes from interval Said Shoon’s crunching tackle on Kiatisuk earned the Oman defender a yellow card and the Thais a free-kick in a dangerous position but Sutee wasted the opportunity by firing the set-piece straight into the Oman wall.

Kiatisuk was in the wars again seven minutes later when he was barged over by Juma Abdullah Al Wahabi, who became the fourth Oman player booked by referee Lee Gi-yong, before Therdsak fired an angle drive into the side netting on the stroke of half-time.

The inaugural AFC Champions League MVP saw his free-kick comfortably held by Oman keeper Ali Al Habsi one minute after the restart before a superb long pass from Kiatisuk deep inside his own half found Sutee in acres of space near the opponent’s penalty area.

Sutee, who has featured in every one of Thailand’s Asian Cup matches since Lebanon 2000, squared the ball to Thai skipper Tawan Sripan who blazed his shot high over the bar.

In the 58th minute Chanvit bolstered his attack by taking off playmaker Therdsak and bringing on striker Pipat, who tested Al Habsi with a low drive four minutes later.

Kosin, who was outstanding in the first-half of the draw with Iraq, had had a quite game up until the 65th minute when he turned Ahmed Hadid’s curling free-kick from the left onto the post.

With 20 minutes left to play Thailand’s persistence finally paid off and it was Pipat and fellow substitute Teerathep who combined for the opener.

Nirut Surasiang played a pass through to Teerathep, who replaced Kiatisuk three minutes earlier, and the BEC Tero Sasana striker whipped in a cross that was side-footed home by the unmarked Pipat at the far post.

Al Ajmi flashed a header wide while Bader Mubarak tested Kosin with a superb turn and shot before Teerathep and Pipat combined again for Thailand’s second eight minutes after they broke the deadlock.

Former Crystal Palace youth player Teerathep got up well to head a long ball into the path of Pipat who controlled the ball with his chest before firing past Al Habsi with authority to complete a win that put the Thais in an excellent position to go through to the last eight.