The Polish world No. 2, who was aiming for her second title in Miami, fell 3-6, 3-6 to the 140th-ranked Eala in their women's singles clash on Wednesday.
The match lasted 1 hour and 41 minutes, public broadcaster Polish Radio’s IAR news agency reported.
Świątek, 23, was given additional security at this year's Miami Open after her team reported that an "aggressive and taunting" fan verbally abused her during a practice session over the weekend.
Her team said the man had previously sent abusive online messages to her through social media, according to a report by the BBC.
"The Miami incident appears to be a direct transition from verbal aggression online to harassment in the real world," the Polish player's team said, as cited by BBC Sport.
Earlier this month, Świątek reached the semifinals of the BNP Paribas Open tennis tournament at Indian Wells, California, where she succumbed 6-7, 6-1, 3-6 to Russia's Mirra Adreeva.
The Polish star in October parted ways with her long-time coach Tomasz Wiktorowski and hired Belgium's Wim Fissette to replace him.
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Source: IAR, PAP, BBC Sport