Samsung may have stolen CES 2019 by announcing the launch date of its upcoming Galaxy S10 (it's Feb. 20, by the way), but it was world's second-largest phone maker, Huawei, that turned out the best phone here at the show. That might not seem like much of a threat when you consider that there were few phones to speak of. Yet, the Huawei Honor View 20 has enough unique features on what will be a midprice device to make Samsung look over its shoulder.

Samsung is currently the largest phone brand on the planet by sales volume, but it's hardly sitting pretty. Phones sales are slowing down, with even trillion-dollar Apple warning investors that it hasn't sold as many new iPhones as expected. Samsung will need its 10th anniversary Galaxy S10 to impress if it's going to keep its place at the top. 

Does Samsung really have anything to fear? Huawei, which ousted Apple to become number-two, is in a tight spot. The company, which is also one of the biggest names in telecommunications equipment, has been banned by governments over fears of spying for the Chinese government, despite Huawei's insistence that it adheres to local laws wherever it operates. Since last year, massive carrier and retailer deals dried up and two of the company's employees have been arrested. 

Although Huawei's business is imperiled, the handsets themselves are on the rise. The Huawei phones we've seen since last CES have outpaced Samsung's flagship models with three rear cameras, like the Huawei P20 Pro and Mate 20 Pro, an in-screen fingerprint reader and flashy finishes and colors, like the stunning Honor View 20 seen this past week at CES. 

(Summer's mid-price Galaxy A9 has three rear cameras, but Samsung has yet to launch a premium phone with the same technology. Then again, Google's top-scoring flagship Pixel 3 retains one rear lens.)

Huawei, too, edged Samsung its AI camera agenda, and introduced photography software that closes the gap with some iPhone features -- like dramatic lighting for selfie photos, and Huawei's version of Apple's "Animoji" that avoids the pitfalls of Samsung's extremely creepy AR Emoji.

Samsung heads into 2019 with the advantage of rock-solid partner support, but flagging momentum. After its third quarter ended in October, Samsung said in a press release that it "achieved solid sales of flagship models" and that "total smartphone shipments remained flat due to decreased sales of mid- to low-end products." Even though Samsung expects sales to rise in 2019, this is hardly confidence-stirring stuff.

Meanwhile, Huawei's sales have grown despite an almost total US shutout (the US is the world's second-largest phone market after China), and its devices are innovating faster. Days before CES, Huawei announced that it sold 200 million units across all its divisions, including the mid-level Honor line.

It's into this mix that the Galaxy S10 will answer the ultimate question of whether or not Samsung can catch up in terms of shelf appeal. There's also Apple to contend with. When CEO Tim Cook unveiled the iPhone X in 2017, it was a radically redesigned device that introduced cutting-edge technology like Face ID, a 3D front-facing camera that maps your face for secure unlocking and gesture controls. 

Samsung is widely expected to give its Galaxy S10 phones a similar face unlocking camera, the first "ultrasonic" in-screen fingerprint reader and a "bright night" camera mode for low-light photos (similar to what Huawei phones and the Pixel 3 phones have). The problem is that while Apple's Face ID gave us something no other phonemaker had, versions of all these rumored S10 features have long appeared on other Android phones. 

Samsung will have to surpass them all to make the S10 sell big, or deliver something surprising and new.

Foldable Galaxy X: The ace up Samsung's sleeve

That something "new" Samsung's betting on to carry it through 2019 will likely be other phones altogether. Samsung has committed to a foldable phone, rumored to be called the Galaxy X or Galaxy F, by the first half of the year. The design is considered the future.

Foldable phones are poised to shake up a phone industry based on flat, bricklike devices. While only one foldable phone currently exists, the Royole FlexPai, which is currently on backorder, the new designs are already credited with ushering in new ways to use your most personal device. 

Phones that open up into larger screen tablets will create more space for people to engage with apps, videos and games. But, as with tablets, they also have the potential to make multitasking easier, or split a screen to give you controls on one side and a viewing area on the other. 2017's ZTE Axon M didn't have a bendable screen -- it connected two separate displays with a hinge -- it showcased different ways to use two displays back-to-back, including a mirror mode that projected the same thing on both screens.

Read: CES 2019 shows the foldable phone revolution will be awkward, but essential

While Samsung is expected to introduce the first foldable phone from a major phone contender, LG, Huawei and others have also said they're developing foldable prototypes. TCL, which makes BlackBerry and Alcatel phones, TVs and panels to sell to other devicemakers, also said it'd make a foldable device in 2020. 

"2019 is about 5G and full display designs," Wayne Lam, an analyst at IHS, told CNET's Roger Cheng. "I would say the market won't get really interesting until 2020."

With Google's support for foldable Android products, you can bet these designs will proliferate.

5G-ready phones are even more important 

If the foldable "Galaxy X" phone is the party animal of Samsung's phone business in 2019, Samsung's first 5G phones are the buttoned-up blazer types that will get the job done. 

Samsung has already pledged four US phones in 2019 to take advantage of the first networks to offer immense 5G speeds with almost zero latency: one each for Verizon and Sprint, and two for AT&T. The hope in having these devices ready even before the networks get going is to make the transition from 4G to 5G networks quicker and smoother than the shift from 3G to 4G.

Read: 6 things you should know about Samsung's 5G phones for 2019

Since the first 5G devices will cost more than their 4G counterparts, expect these handsets to look more like today's Galaxy S9 than a wacky phone that folds down the center. Samsung won't double up its risk -- or increase the price of an already expensive foldable phone -- by putting them both together at first.

In fact, rumors point to a 5G variant of the Galaxy S10. The tech giant did show a 5G prototype Samsung phone at its CES booth -- behind glass -- but wouldn't tell us which carrier it's destined for, or how its final design might change.

Foldable phones might not pan out, or it could take years for the industry to hone the materials, apps and overall look that works best. But 5G phones are a sure bet that will allow Samsung to remain on the forefront as networks slowly replace LTE with 5G. This transition will take time, and the first 5G phones are expected to be costly. 

In the meantime, the 4G Galaxy S10 will be waiting, and so will its fiercest rivals.

Samsung declined to comment on this story.

Galaxy S10 launch date confirmed: Feb. 20 at Samsung's Unpacked event in San Francisco

Samsung 5G phone prototype pops up at CES 2019

CES 2019: See all of CNET's coverage of the year's biggest tech show.