In the final match of the first round, the efficient Motorola Moto X took on the brute force of the Sony Xperia Z2. So let's see how they compared.
Things started evenly as we compared the phones' design. The Sony definitely felt more premium with its metal body. But it felt a little big in the hand compared to the lighter Motorola with its ergonomically designed plastic back case.
The Xperia Z2 started to get ahead when we compared the screens. Its 5.2" Full HD display uses the same tech as Sony's top TVs, making and everything look colourful and really sharp. But it wasn't completely one-sided as the Moto X has a superb 4.7" HD screen.
We thought that the Sony might get away from the Motorola when it came down to speed. But although the Moto X looks slower on paper, it works much better with its software so runs just as quickly.
The phones kept up the close match through the camera comparison too. The Moto X can take great shots really quickly and easily thanks to fun software that lets you start the camera with a twist of the wrist. And the Xperia Z2's photos are incredible when the camera's in manual mode.
The Moto X scored big for ease of use. Its always-listening voice controls let you use your phone without touching it. That's perfect for driving and works so well that you end up using it when it's sat on the sofa next to you. The Xperia Z2, on the other hand, felt a little fiddly to use at times.
But the phone from Japan got its own back with its super durable and waterproof body. You really can use the phone anywhere. It can even take photos under water. With the Moto X, you'd probably want to be careful using it in the rain.
At the end of the day, the Xperia Z2 had the legs to keep running long after the Moto X was tired out. It has a massive battery and software that uses very little power so you can happily get two day's use from a single charge. The American phone, on the other hand, will only last you a day.
So this match turned out to be the tightest we've seen in the first round of the 2014 Mobile World Cup. But the Sony Xperia Z2 just edged it for Japan, setting up a semi-final against the Nokia Lumia 930 from Finland.
Next week (Monday 23rd June) sees Taiwan take on local rivals South Korea in the first semi-final of the 2014 Mobile World Cup.