Thailand coach Mano Polking warned his men not to get carried away following their 2-0 win over Vietnam in the semi-final first leg of the AFF Suzuki Cup on Thursday.
A first-half brace from playmaker Chanathip Songkrasin put Thailand in a commanding position at the break at Singapore's National Stadium.
Things could have been even worse for the defending champions if not for a penalty save by Vietnam goalkeeper Tran Nguyen Manh in the 84th minute as he denied the Thai captain his hat-trick.
The second leg will take place on Sunday at the same venue.
The winners will meet hosts Singapore or Indonesia in the final, to be played over two legs on Dec 29 and Jan 1.
Polking, in his first tournament in charge of the War Elephants, was full of praise for his side but also cautioned them not to go overboard.
"We have a small advantage with the two goals. It's an important first step but it's not done yet. We still have several points to adjust and should do better than this," said the Brazilian.
"We know that we have to adjust some things and know we can play better than this but we knew it was important to get the result."
It was Thailand's first ever win against Park Hang-Seo's Vietnam.
"Everyone knows that coach Park has a good record against Asean teams and we wanted to stop this record. We know very well that Thailand can beat Vietnam but we still have 90 minutes left and we must be focused and win it again," said Polking.
While a large number of Thai fans complained about Vietnam's hard-tackling approach, Polking said he did not have a problem with this.
"We know that the Vietnamese play aggressively and have done very well when playing like this but everything was fine and there was not much aggressiveness. This is football and we don't have any problem about that," he said.
Chanathip, who was named man of the match, gave credit to the coach and his teammates for his fine performance against the Golden Star Warriors.
"It's a victory for the team. We helped each other. Everybody chased the ball. However, our job is not yet finished as we still have one more match to play and we have to get a result again," said Chanathip, who plays for Japan's Consadole Sapporo.
He admitted that he felt sorry for the missed penalty but said this would not affect his performance in the second leg.
He also said he wanted to win the title as a birthday gift for his mother.
On Thursday, Vietnam also had their chances, hitting the woodwork twice.
They had a penalty appeal waved away by the referee in stoppage time as the ball struck the hand of substitute Weerathep Pomphan.
"I don't wish to talk about the referee. The referee must go and review to see about his judgement," said South Korean Park.
"It's unfortunate that we conceded an early goal from a mistake but I think we played well and fought hard so now we must focus on the next game."
A long pass on the counter-attack saw Nguyen Phong Hong Duy slip over as he scrambled back to try and cut things off, only to lay prone on the turf and watch as Chanathip raced past him to collect the ball and see his shot come off goalkeeper Tran and bobble into his goal.
If there was a touch of good fortune about Thailand's opener, the second was one of pure class as some superb one-touch football saw Chanathip and Teerasil Dangda exchange passes before the diminutive star worked a one-two with Sarach Yooyen and slid his shot past Tran to make it 2-0 in the 23rd minute.
Bolkiah joins Chonburi
Thai League 1 side Chonburi have signed Brunei international Faiq Jefri Bolkiah from Portugal's Maritimo, the club announced yesterday.
The 23-year-old midfielder is dubbed the "richest footballer in the world" as he is a member of the Bruneian royal family and nephew of Hassanal Bolkiah, the current Sultan of Brunei.