(CNN) -- Saudi Arabia and Japan made stuttering starts to their bids to win a record fourth Asian Cup title on Sunday.
The Saudis, beaten in the previous final four years ago by Iraq, suffered a shock 2-1 defeat by Syria in their opening game in Qatar.
Japan, the 2004 champions, earlier needed a late equalizer to snatch a 1-1 draw with Jordan in Group B's first match.
Syria have never made it to the quarterfinals in four previous attempts, the last being in 1996, but boosted their hopes of progressing thanks to two deflected goals from midfielder Abdulrazak Al Husein at Ahmed bin Ali Stadium in Al-Rayyan.
He broke the deadlock seven minutes before halftime when his shot from outside the penalty area went in off the head of Abdullah Shuhail, but Syria's goalkeeper Mosab Balhous gifted Saudi an equalizer with half an hour to play.
The captain let a tame header by substitute Taiseer Al Jassam slip past him and into the net, but Al Husein saved his blushes just two minutes later as he again pounced on a loose clearance and saw his shot take a significant diversion into the Saudi net.
Syria's Romanian coach Tita Valeriu was delighted after having only recently taken control of the team.
"I didn't expect to win but I expected us to play well," he said in quotes reported by the AFP news agency. "I had only a very short time to coach the team but we used a formation that worked very well. That was the key."
The result puts more pressure on the Gulf nation's coach Portuguese coach Jose Peseiro, who was failed to guide the team to the 2010 World Cup in South Africa.
"We didn't deserve to lose, but we lost," he said. "We are disappointed with the result, but not the spirit.
Japan appointed Italian coach Alberto Zaccheroni after Takeshi Okada stood down in July, having taken the "Blue Samurai" into the second round of football's biggest tournament before losing on penalties to Paraguay.
Zaccheroni led Japan to a historic 1-0 friendly win over South American superpowers Argentina in his first match in charge, but the former Inter, AC Milan and Juventus coach was disappointed by his team's efforts at Doha's Qatar SC Stadium.
Jordan, playing at the tournament for just the second time, took the lead right on halftime when Hasan Abdel Fattah's shot deflected in off Maya Yoshida -- who made amends with a headed leveler two minutes into second-half injury-time.
"I am not satisfied with the result, especially in the first half," Zaccheroni said.
"We must accelerate the speed of our play. We failed to finish on chances. I expect other Asian teams will fight like Jordan. We must readjust ourselves with that in mind."
The 16-team tournament continues on Monday, as Group C kicks off with outsiders India playing Asia's top-ranked team Australia and then two-time champions South Korea taking on Bahrain.