MacKinnon scored the 1-1 equalizer early in the first period and then hammered home the 3-1 jawbreaker — a one-time laser from the right wing circle, 4:14 into the third period.
Ex-Hurricanes forward Martin Necas tidied up the scoresheet, and sent the Bruins dashing for their charter, with his empty-net goal with 2:37 remaining.
The Bruins, who wrap up their three-game road trip Sunday night in Salt Lake City, fell to 3-3-0. The powerhouse hosts outshot the Bruins, 38-14, and finished with a lopsided 87-39 advantage in shot attempts.
Johnny Beecher, inserted into the Bruins lineup for the first time this season, scored the lone goal for Marco Sturm’s wilting stick carriers.
Over the last three games, all losses, the Bruins held a lead for a cumulative 7:16 of the 180 minutes. Their three opponents — the Lightning, Golden Knights, and Avalanche — led for 144:15, a figure that represents 80 percent of the playing time. Playing uphill hockey is not a prescription for success.
Like the road-trip opener in Vegas, the Bruins scored first . . . and then the Bruins quickly gave up the lead. Even worse for the Bruins, they then saw the hosts move out front, 2-1, on a long-ranger slapper by former Northeastern defenseman Josh Manson, and that lead held up into the first intermission.
Beecher, making the most of his speedy legs, gave the visitors a 1-0 lead only 3:11 into the action. He alertly put home a forehand redirect near the left post off Charlie McAvoy’s slap pass from the top edge of the left wing circle. Colorado goalie Scott Wedgewood (13 saves) overplayed what he sized up as a McAvoy shot, leaving open the far side of the net for Beecher to make the drive-by deposit.
The Avs were back square at 7:08, cashing in on a Bruins miscue. David Pastrnak attempted to push the puck into middle ice from his spot near the bench. The revved-up Avalanche turned it into a lightning-quick transition, with MacKinnon blitzing down Broadway and finishing past Jeremy Swayman (34 stops) for his fifth goal of the season.
Beecher’s goal came on the first shot by the Bruins. Ditto for Colorado, which was being booed by the home crowd for lack of offensive action for about 15 seconds before Pastrnak’s fumble set up the equalizer.
Manson’s goal came on the second shot against Swayman, who barely flinched as the shot sailed into the net — clear indication that he never saw it. Manson was set up off a faceoff to Swayman’s left, and he squeezed off his shot from near the blue line. Brock Nelson set up a screen down low and the puck was in the net at 10:22.
The two clubs split 14 shots in the first period, but the Avalanche had a clear margin in shot attempts, 23-15.
Hampus Lindholm, sidelined since the first period of Game 2, made it back into the lineup and was paired with Andrew Peeke. Lindholm also teamed with Mason Lohrei on the Bruins’ second power-play unit. The smooth Swede skated well after a layoff of three-plus games, due to what is believed to have been a groin or hamstring pull.
The little bit of good news for the Bruins in the middle period is that they lost no ground on the scoreboard. They were still down only a goal, 2-1.
However, the more offensively slick Avalanche controlled flow of play throughout the second frame, landing 16 shots on Swayman while the Bruins mustered only two on Wedgewood.
For a third game in a row, the Bruins just could not match the opposition for pressure and execution in the offense zone.
Kevin Paul Dupont can be reached at kevin.dupont@globe.com.
