Power From Hell by Onslaught, from their 1985 album also titled Power From Hell. Thrash metal.

Main Riff (After the Power from Hell is released) - 0:31
  [----PM---]          [---PM---]   [-PM-]
E-----------------------------------------------------------------------|
B----------------------------------------------24ths--------------------|
G----------------------------------------------4h5p4h5p4h5p4h5p4h5p4h5p4|
D------------------thirds-----------------------------------------------|
A-2--------------5-{8\7\5}-2---------3/5-2------------------------------|
E-0-000000000000-3-{6\5\3}-0-0000000-1/3-0-0000-------------------------|X9
                
 Chorus - 1:16
|------------------------------------------------------------------|
|------------------------------------------------------------------|
|------------------------------------------4h5p4h5p4h5p4h5p4h5p4h5p|
|------------------------------------------------------------------|
|-7---(7)---5-(5)-3-(3)-2---(2)--3/5-2--(2)------------------------|
|-5---(5)---3-(3)-1-(1)-0---(0)--1/3-0--(0)------------------------|X2

 Rpt Verse (Main Riff - 1:26
 Rpt Chorus - 1:57

Bridge - 2:07 
 [--PM--]  [PM]  PM     [--PM--]  [PM]   PM
|--------------------------------------------------|
|--------------------------------------------------|
|--------------------------------------------------|
|--------------------------------------------------|
|-2-2-2-2-3-2-2-3---5-(5)--2-2-2-2-3-2-2-3---8\5---|
|-0-0-0-0-1-0-0-1-0-3-(3)--0-0-0-0-1-0-0-1-0-6\3---| 3X

  Guitar 1
  [--PM--]  [PM]  PM     [--PM--] [PM]   Guitar 1          Guitar 2
|--------------------------------------- ----------------| ----------------|
|--------------------------------------- ----------------| ----------------|
|--------------------------------------- 7-5-------------| ----------------|
|--------------------------------------- ----7-6-5-------| 7-5-------------|
|-2-2-2-2-3-2-2-3---5-(5)--2-2-2-2-3-2-2 ----------7-6-5-| ----7-6-5-------|
|-0-0-0-0-1-0-0-1-0-3-(3)--0-0-0-0-1-0-0 ----------------| ----------7-6-5-|

Riff - 2:29
 [-PM-] [-PM-] [-PM-] [-PM-]  [-PM-] [-PM-] [-PM-] [-PM-]
|------------------------------------------------------------|
|------------------------------------------------------------|
|------------------------------------------------------------|
|------------------------------------------------------------|
|------5------5------5------7-------5------5------5------8\7-|
|-0000-3-0000-3-0000-3-0000-5--0000-3-0000-3-0000-3-0000-6\5-| 4X

 Verse (Main Riff) - 2:49
 Chorus - 3:18

 Main Riff X4 - 3:29

 Main Riff X4 - 3:49
 (Rhythm guitar for solo)

 Verse (Main Riff) - 4:09
 Chorus - 4:39

Outro - 4:50   
 [----PM---]           [----PM---]
|--------------------------------------------|
|--------------------------------------------|
|--------------------------------------------|
|-2------------5-/8\7\5-2------------4/5\4---|
|-0--0-0-0-0-0-3-/6\5\3-0--0-0-0-0-0-2/3\2---|
|--------------------------------------------| 4X 
 
    [----PM---]           [----PM---]
|--------------------------------------------------------|
|--------------------------------------------------------|
|------------------------------------3-2---2-------------|
|-2------------5-/8\7\5-2----------------3---3-2---2--2--|
|-0--0-0-0-0-0-3-/6\5\3-0--0-0-0-0-0-------------3-0--0--|
|--------------------------------------------------------|

Thanks for your heavy metal support! Keep on thrashing!