Kyrie Irving scored 27 points while LeBron James added 24 as the Cavaliers dominated almost from start to finish to the delight of their home fans at the Quicken Loans Arena.
The 31-point rout was Cleveland’s biggest ever victory in a playoff game.
The Cavaliers went into the game well-rested after wrapping up back-to-back 4-0 sweeps in their opening two postseason series.
Toronto by contrast had been forced to make a quick turnaround after only clinching a 4-3 series victory over the Miami Heat in their conference semi-final on Sunday.
On the evidence of Game One, few would bet against James and the Cavaliers making short work of the Raptors.
The outcome of the contest was effectively decided in a devastating period of Cleveland dominance which began late in the first quarter and continued to the half-time buzzer.
A 28-27 Toronto lead with around one minute left on the clock in the first quarter rapidly became a 39-28 lead for Cleveland as they reeled off 12 unanswered points.
The Raptors were always struggling to stay in touch and with Irving, James and Love in form, it rapidly became an exercise in damage limitation for the visitors, playing their 15th game of the postseason.
The Cavs quickly sprinted into a 49-30 lead and although the Raptors hit back to narrow the gap to 54-42, it was only a temporary staunching of the tide.
Cleveland produced another burst of points and by half-time had surged into a 22-point lead at 64-44, Toronto’s woe exacerbated by consecutive air balls to close the half.
The torture continued in the third quarter as the Cavaliers maintained a healthy double-digit lead against a Toronto side unable to find any answers on defense.
James’ buoyant mood was typified by a steal which finished with the two-time NBA champion racing up the court for an emphatic slam dunk to make it 81-56.
It got worse for the Raptors near the end of the third, with the Cavaliers opening up what at that point was the biggest lead of the night, a 28-point margin of 95-67.
That soon became 30 points in the fourth quarter, with Cleveland surging into a 97-67 advantage as the slaughter continued before the score settled at 115-84.
DeMar DeRozan led the scoring for the Raptors with 18 points, but it was a miserable night for Kyle Lowry. The Toronto talisman who excelled against Miami on Sunday finished with only eight points.
Game Two of the series takes place on Thursday in Cleveland.
Russell Westbrook inspired a second-half fightback as the Oklahoma City Thunder came from behind to beat the Golden State Warriors 108-102 in the opening game of the Western Conference finals on Monday.
Westbrook poured on 27 points as the Thunder overturned a 60-47 halftime deficit to snatch victory in a pulsating clash between two of the most potent attacking units in the NBA.
Westbrook also chipped in with 12 assists and six rebounds while team-mate Kevin Durant finished with 26 points as the visitors silenced the Golden State home crowd at the Oracle Arena.
Game Two in the best of seven series takes place in Oakland on Wednesday.
After a stunning upset of the San Antonio Spurs, can the Thunder keep their success going against the defend champions? The match-up is filled with star power with two-time reining MVP Stephen Curry on one side and OKC’s duo of Kevin Durant and Russell Westbrook on the other.
In the East, can the Raptors slow down the Cavaliers and avoid becoming the third victim of a Cleveland sweep? LeBron James and Co are well rested heading into the match-up, while Toronto were taken seven games in each of the first two rounds.
Listen to our analysis and breakdown of both series, as well as predictions on which two teams will meet in the Finals.