It's the latest of a number of firsts for Saudi women; later this year, they'll be able to drive. "But thank god that it came in the right time, and hopefully what's to come will be even more lovely for women". "I am very proud to be a witness of this massive change", she said.
Reema said the day marked a historic moment for the kingdom.
A hashtag, translated as "the people welcome the entry of women into stadiums", was used tens of thousands of times in two hours as the match took place.
The Saudi government said last week women would be allowed to attend a second match on Saturday and a third next Thursday.
In 2015, a Saudi woman who tried to attend a football game in Jeddah was arrested after local media said she was spotted by security officers "deliberately disguised" in pants, a long-sleeve top, a hat and sunglasses to avoid detection.
Saudi Arabia's royal family and religious establishment adhere to an austere form of Sunni Islam and Islamic codes of behaviour, which are strictly enforced. The women however had to enter through designated turnstiles for women and families.
"Family sections" also allowed married couples, direct relatives and groups of friends to sit together.
The move is part of Crown Prince Mohammed bin Salman's ambitious project to modernise the Saudi society and boost its economy.
Set to inherit a country where more than half the population is under 25 years old and hungry for change, the young crown prince has looked to boost his popularity by curbing almost four decades of deeply entrenched ultraconservative influence.