While things initially got off to a slow start, with both tigers described by the zoo as "cautious", they quickly turned serious and Asim began to get aggressive with his female counterpart.
The male, Asim, killed long-term resident Melati on Friday, 10 days after he was brought over from Denmark.
Loud noises, flares and alarms that the zoo staff used to distract the pair did not help control the situation.
The zoo had hoped the pair would be compatible as their previous male tiger, Jae-Jae, sired seven cubs with Melati before he was moved to French zoo Le Parc des Félins, on 30 January. Despite the intervention of staff, he attacked Melati, mauling her to death.
Zoologists had hoped the two tigers would breed as part of a Europe-wide tiger conservation program for the endangered Sumatran subspecies.
After witnessing sufficient evidence and "obvious positive signs", the zoo felt comfortable enough to open the adjoining door and introduce the two predators on Friday morning.
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Meet our latest arrival ❤️ Seven-year-old Asim, whose name means "Protector" in Arabic, has moved from @ReeParkSafari.
Ten-year-old Melati, who had been at London Zoo since 2012, was mauled by Asim shortly after they were introduced and could not be saved, despite the efforts of staff.
Everyone at ZSL London Zoo is devastated by the loss of Melati, and they are heartbroken by this turn of events, they said adding that as with all big cats, introductions, however carefully planned, are always considered to be high risk.
"Zookeepers were eventually able to secure Asim in a separate paddock so that they could safely get to Melati where our vets confirmed that she had sadly died".
The zoo has been forced to shut down its tiger exhibit for the time being as it deals with the aftermath of the incident. It is estimated that less than 400 of the species remain in the wild today.
The zoo's head tiger keeper Kathryn Sanders said last month: 'Asim arrived yesterday after catching the ferry from France and immediately made himself at home in his new, cosy den. In Indonesia, anyone caught hunting tigers could face jail time and steep fines.