Episode 22 of "MacGyver"
s01e22 The Assassin

Posing as an assassin purchasing a bomb, MacGyver manages to catch a master killer, Piedra, before he attempts an assassination on an archbishop. But Piedra, a master of MacGyver-style improvised assassination (he rigs a blowgun out of a papercup, a needle, and a pea!) manages to escape from government security at a safehouse in the city. Confusing matters, Teri Ross, a woman posing as a call girl (to confuse those who may be watching for the assassin), is trying to kill Piedra in revenge for him killing her sister. Unaware that MacGyver is playing the part of Piedra, she threatens to kill him until he seizes her firearm and explains he is not the assassin that murdered her sister. Meanwhile, Piedra, a master of disguise, could be anywhere and the archbishop's guards are reluctant to let MacGyver near, fearing he is Piedra. He eventually outsmarts the head bodyguard of the archbishop's to call Pete and request backup. He also explains he is not Piedra, and then goes to work helping the archbishop's guards look for the clever assassin. In a clever ploy, MacGyver poses as the archbishop and roots out Piedra. But Piedra kicks him and the guards away and runs to find the archbishop. Before he gets there, MacGyver, hot on his trail, attacks him on a patio, safely from the archbishop. MacGyver lunges at Piedra, causing him to lose his poisionous needle, intended for the archbishop. Piedra pulls a gun and MacGyver trips him, causing Piedra to fall on his own needle. Piedra is seconds away from dying, but he is still conscious enough to use his gun and kill him. Pete and the feds have arrived by this point and the guards have recovered. They all rush near the two, but there is nothing they can do. Will Piedra die before he can kill MacGyver...?