The Huawei Y9 Prime is priced at Rs 15,000 (after cash back offers) while Vivo S1 costs Rs 17,990.
In terms of design aesthetics, the Huawei Y9 Prime wins, thanks to the brand's legacy of bringing brilliantly designed phones into the market.
With its Emerald Green and Sapphire Blue variants, the Y9 Prime is a clear winner.
The 6.59 inch full view HD+ bezel-less display is a cut above the Vivo S1's 6.38 inch full HD+ Super AMOLED display.
The Vivo S1's notch takes up much of the screen space.
The Y9 Prime features a HiSilicon Kirin 710F processor, far ahead of the MediaTek P65 processor that the Vivo S1 has.
In the storage department, Vivo S1 lags behind Y9 Prime. While both the smartphones sport 4GB RAM and 128GB storage, the Huawei device allows an expandable storage option.
In terms of camera, Y9 Prime sports 16MP main camera with 8MP ultra-wide shooter and a 2MP depth sensor.
Vivo has fitted S1 with three rear cameras -- a 16MP primary camera with a Sony sensor, a secondary ultra-wide-angle one with a 120-degree field of view and a 2MP depth sensor.
Y9 Prime features an AI enabled automatic pop-up selfie camera, whereas Vivo S1 uses the notch technology to make space for its selfie camera.
While Y9 Prime has the conventional fingerprint scanner at the back, Vivo S1 features an in-display fingerprint scanner.
In terms of software, the Y9 Prime features the advanced EMUI 9.0 based on Android Pie which will soon be updated to EMUI 9.1.
The Vivo S1 with the Funtouch OS has its own limitations. The phone would soon get Andoid Q update, according to the sources.
Overall, the Huawei Y9 Prime outpaces Vivo S1 in terms of design, look and feel, hardware, software and price.