The Lynx used first-period goals from Roberts and Kody Dubie, a pair of sophomores, to build a 2-0 lead over the seventh-seeded Wolves at the McDonald Center in Eagle River.
But Wolves goaltender Kyle Haken (28 saves) held the Lynx in check, and a goal midway through the second period from Alex Browning and one with 3:24 remaining from Connor Sperry forged a 2-2 tie.
When Eagle River's Bryan Grant was whistled for slashing with 1:45 left, Dimond coach Dennis Sorenson used his timeout. Roberts, who assisted on Dubie's goal, scored with the man advantage off assists from Kyle Clapper and Max Fairchild.
Henry Rubey stopped 13 shots for Dimond.
In two regular-season meetings, Dimond beat Eagle River 5-0 and 8-0.
The Lynx advanced to a Thursday semifinal against the winner of tonight's opening-round game between East and Chugiak.
All four CIC semifinalists qualify for the state tournament.
And that means top-seeded South earned its state tournament berth with Monday night's 10-0 cruise past eighth-seeded Bartlett at Ben Boeke Arena.
South, which lost just twice in the regular season, was sparked by two goals each from Kyle Simmons, Raymond Redmond and Ashton Ondra. Simmons added a playmaker (three assists), and Redmond and Ondra each furnished a helper.
Kris Smith added one goal and two assists for the Wolverines, who outshot the Golden Bears 48-5. That made an easy night for South goaltender Trevor Gutierrez, who also picked up an assist.
Bartlett goalie Stephen DeBoer racked 38 saves.
South advanced to a Thursday semifinal against the winner of tonight's match between West and Service.
Dimond 3, Eagle River 2
Eagle River 0 1 1 -- 2
Dimond 2 0 1 -- 3
First Period -- 1, Dimond, Roberts, 6:41; 2, Dimond, Dubie (Austin, Roberts), 14:44. Penalties -- Eagle River 0 for 0 minutes, Dimond 0 for 0.
Second Period -- 3, Eagle River, Browning, 6:46. Penalties -- Eagle River 3 for 6, Dimond 3 for 6.
Third Period -- 4, Eagle River, Sperry, 11:36; 5, Dimond, Roberts (Clapper, Fairchild), 14:36 (pp). Penalties -- Eagle River 1 for 2, Dimond 0 for 0.
Goalies -- Eagle River, Haken 10-7-11--28; Dimond, Rubey 4-4-5--13.
South 10, Bartlett 0
Bartlett 0 0 0 -- 0
South 2 4 4 -- 10
First Period -- 1, South, Simmons (Shepherd, Gutierrez), 5:31; 2, South, Redmond (Shepherd, Simmons), 14:16. Penalties -- Bartlett 2 for 4 minutes, South 2 for 4.
Second Period -- 3, South, Ondra (Moss), 2:37; 4, South, Simmons (Redmond, Welch), 4:07 (pp); 5, South, Moss (Smith, Carle), 5:32; 6, South Redmond (Simmons, Wells), 10:51. Penalties -- Bartlett 3 for 6, South 1 for 2.
Third Period -- 7, South, Shepherd (Simmons), 2:29; 8, South, Wells (Frazer), 4:41; 9, South, Smith (Ondra, Head), 7:25; 10, South, Ondra (Smith, Carle), 11:02. Penalties -- Bartlett 2 for 4, South 1 for 2.
Goalies -- Bartlett, DoBoer 15-13-10--38; South, Gutierrez 0-4-1--5.
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