Asia Cup: Five things to learn

- Home advantage counts -

It has been a long time since Iran or Saudi Arabia were kings of Asia but with the tournament back in the Middle East, they have looked in ominous form. Iran, Asia's top-ranked team, swamped Yemen, the lowest in the competition at 135 on the FIFA listings, 5-0 in the biggest win of the first round. Iran haven't lifted the trophy since 1976, when they completed a run of three straight victories -- two of them on home soil. 

Three-times winners Saudi Arabia, who last won the title in UAE, a short hop over their shared border, in 1996, were also impressive in their 4-0 win over North Korea. After Jordan stunned defending champions Australia, and Uzbekistan became the only side from outside the region to beat a Middle Eastern team, it's tempting to think that home comforts count for much.

- Don't mind the gap -

Reputations increasingly mean little in international football but when Turkmenistan and the Philippines are playing the continent's best, expectations are understandably low. However, a thunderous first-half strike put Turkmenistan 1-0 up against four-time winners Japan, who eventually escaped 3-2, while the Philippines repeatedly troubled South Korea, runners-up in 2015, before narrowly losing 1-0.

They were far from isolated incidents: Jordan dealt a heavy blow to Australia's title defence with a 1-0 upset win, and Kyrgyzstan were 1-0 up against China before an own goal put Marcello Lippi's team on course for a face-saving 2-1 victory. Meanwhile, India's 4-1 win over Thailand rocked the record five-time Southeast Asian champions so much that they promptly sacked their coach, Milovan Rajevac.

- Bring me Son-shine -

Despite the surprises and moments of quality so far, a dash of star power would not go amiss and it's not just South Korea who are eagerly awaiting the arrival of Son Heung-min. The Tottenham Hotspur forward will significantly boost the Korean front line when he joins the competition after Friday's game against Kyrgyzstan, under a deal struck with his Premier League club.

Son led South Korea to the Asian Games title last year, and memorably struck their second as they knocked holders Germany out of the World Cup in Russia. He will also help raise the profile of a tournament which is not blessed with a great number of personalities well known outside of Asia, apart from some of the coaches who include Lippi, Sven-Goran Eriksson, Carlos Queiroz and Hector Cuper.

- It's not just cricket -

Indian sports fans have a new idol to love -- and he's not a cricketer. When Sunil Chhetri plundered a brace in the shock win over Thailand, he moved past Lionel Messi and behind Cristiano Ronaldo in the goal-scoring charts for active international players. Chhetri's achievement added extra excitement as India celebrated their first Asian Cup win since 1964. A strong run in the tournament will do India's burgeoning football scene no harm at all but despite the success, headlines remained dominated by cricket as it coincided with India sealing their first Test series win in Australia.

- Politics never far away -

Qatar's journey to UAE in the middle of the Gulf blockade was never going to be easy but so far they have dealt with the situation admirably, shrugging off any outside distractions to beat Lebanon handily in their opening match. It is the first time Qatar's national team has visited UAE since the start of the crisis in the middle of 2017, when neighbouring countries cut ties and enforced a blockade of the resource-rich state which will host the 2022 World Cup.

Sanctions-hit Iran also complained of a variety of problems in the build-up to the tournament, while Yemen are in the midst of a full-blown war and humanitarian crisis, Syria have long been wracked by conflict and Iraq's situation remains turbulent.