Artists from 43 countries, majority European, are taking part.
Each participating country has to submit an original song that's performed live on television and radio, after which votes are cast to determine a victor.
Netta has already picked up an OUTtv award after winning a vote among the contest's LGBT fanbase.
The best Eurovision year Portugal ever had, until 2017, was a 6th place 21 years ago in Oslo. The "Big Five" countries - the UK, Germany, Italy, Spain, and France, and the host country, Portugal, are automatically in the final.
Did Selena Gomez just throw shade at her own Met Gala look?
Glittering in a one shoulder Versace gown Gigi, 23, looked ethereal as she posed alongside the Wolves hitmaker. Maybe, but what received the most attention on social media was her orange tan.
Supporting Jessica on her Eurovision journey is her boyfriend-of-nine-years Themeli Magripilis.
The monster-costumed metal band Lordi made Eurovision history in 2006 when it became the first hard rock act and the first Finnish entry to win the contest, with its song "Hard Rock Hallelujah".
O'Shaughnessy performed "Together" in the semi-final last night, and dancers Kevin O'Dwyer and Alan McGrath recreated the dance from the video, eliciting screams from the crowd when they appeared on the set.
Google Maps is trying to out-Yelp Yelp... and it might succeed
For example, a Map user can create a list of his favorite restaurants and send it to a friend or family member who is visiting. The higher the number, the more likely Google thinks that the person will enjoy visiting this destination.
The finals start at 5am (AEST) on Sunday. 43 countries are participating.
Over 200 million people across the world tune in.
In Australia, SBS is the only broadcaster with rights to Eurovision.
The actual Grand Final running order will be determined and publicly announced after the end of both semi-finals on Thursday evening, when we'll finally know all the 26 contenders of the 2018 Eurovision trophy!
Rep: Manziel hospitalized after med reaction
Manizel was reportedly in town to attend a concert and play in a golf tournament hosted by former Texas A&M teammate Mike Evans . It sounds like Johnny Manziel is going to be just fine. 'It seems like he had a reaction to an adjustment in his prescription .
It will be broadcast simultaneously on giant screens on the city's main Commerce Square overlooking the Tagus river, where music lovers can party for free with live shows throughout the event until the May 12 finals.