The 32-year-old Russian dominated every round, masterfully cutting off the ring and landing left jabs at will before Pascal's trainer Freddie Roach put a stop to the slaughter before the start of round eight -- giving Kovalev a seventh-round technical knockout.
This was the Canadian's first fight with six-time trainer of the year Roach, but the outcome was virtually the same as his March light heavyweight fight against Kovalev, which ended with an eight-round TKO for the Russian.
Kovalev retained his World Boxing Association, International Boxing Federation and World Boxing Organization titles as he improved to 29-0-1 with 26 knockouts.
Kovalev knocked Pascal down in the first round with a straight left jab but the referee ruled it a slip.
By the third round Kovalev was landing punches at will against Pascal, whose only hope was to go for a knockout punch.
But Pascal's legs were already going and he looked wobbly as he tried in vain to get away from Kovalev's superior punching power.
Kovalev notched his eighth title defence since winning his first belt with a fourth-round knockout of Nathan Cleverly in 2013.
Pascal, who struggled to win a 10-round decision over Yunieski Gonzalez in his last fight, came in as the heavy underdog. He dropped to 30-4-1 with 17 knockouts.