The Ambush in Rio de Janeiro was the first open confrontation between Bruce Banner and Emil Blonsky.
Bruce Banner lived in Rio de Janeiro as a mechanic in a soda-bottling company. Martina, a co-worker whose apartment was below his, had a crush on him. He had recently helped her when she was being sexually harassed by another co-worker.
General Thaddeus Ross assembled a team to capture Banner. General Joe Greller had gotten Russian-born British special Emil Blonsky to lead the team. A drop of Banner's blood fell into a soda and was ingested by a customer in Milwaukee. Major Kathleen Sparr told Ross while he was in the Pentagon about a man in the hospital suffering from Gamma Radiation poisoning.
General Thaddeus Ross and the Strategic Operations Command Center located Bruce Banner's house and burst in to shoot him with tranquilizer ammo, but Banner fled through the window and momentarily hid with Martina, one of his co-workers, at her house, in order to deceive the military.
Emil Blonsky and the other soldiers pursued Banner through the streets and rooftops of Rocinha, while Banner tried to slow down his heart rate to prevent his transformation.
While fleeing, Banner came across General Ross, realizing he was the man behind the chase, and also a man who almost got into a fight with him when Banner prevented him from harassing Martina earlier at the factory. This man also pursued Banner with his friends to the bottling factory in order to beat him.
Blonsky located Banner in the factory and approached to witness the appearance of Hulk, as the transformation was triggered by the men beating Banner. Hulk incapacitated and killed most of the men and the soldiers except Blonsky, sparing him while Blonsky watched in astonishment. Banner escaped from the factory and fled into the jungle.