PC Malik Khan, who was part of the Uxbridge North team, carried out the attack on June 12 2016, and was convicted of common assault by beating at Reading Magistrates Court on May 16.
At a sentencing hearing on June 6, the 29-year-old was given a three-year restraining order as well as a community order to complete 120 hours of unpaid community work within 12 months.
Khan, of Australia Avenue, Maidenhead, was ordered to pay £620 in costs and an £80 victim surcharge.
A special case hearing held on Tuesday (September 5) found Khan had breached Standards of Professional Behaviour in such a way that the the only appropriate action was dismissal without notice.
Assistant Commissioner Pat Gallan, who chaired the hearing, said: "PC Khan's behaviour fell well below the standards that must be expected of a police officer.
"The conviction of any police officer for such an offence will very obviously undermine that trust the public places in us, therefore the only appropriate outcome is dismissal."
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