 The first blow took the Soviets completely by surprise when the 2nd Panzer Group , returning from the south , took Oryol , just 121 km ( 75 mi ) south of the Soviet first main defense line . Three days later , the Panzers pushed on to Bryansk , while the 2nd Army attacked from the west . The Soviet 3rd and 13th Armies were now encircled . To the north , the 3rd and 4th Panzer Armies attacked Vyazma , trapping the 19th , 20th , 24th and 32nd Armies . Moscow 's first line of defense had been shattered . The pocket eventually yielded over 500 @,@ 000 Soviet prisoners , bringing the tally since the start of the invasion to three million . The Soviets had now only 90 @,@ 000 men and 150 tanks left for the defense of Moscow . 
