The Coldwater, Ont., native entered the match 0-2 but staved off elimination with a crucial three-point shot in the seventh to break a 4-4 tie.
Howard's rink is now 1-2, while Edin's is 2-1.
Elsewhere at the National, Mike McEwen notched three in the fourth and beat Brad Jacobs 6-2. The Winnipeg rink remains undefeated at 3-0. The Sault Ste. Marie, Ont., club is now 2-1.
Kevin Martin scored three to break a tie in the sixth and held on to beat Steve Laycock 6-4. Martin's Edmonton rink improved to a 3-0 record to stay par with Kevin Koe atop Group C. Laycock's Saskatoon club is 1-2.
Jeff Stoughton took a one-point lead in the seventh and poured it on in the eighth to beat Mark Kean 6-2. Stoughton's Winnipeg rink is 1-2, tied with Kean's Toronto club.
Thomas Ulsrud earned his first win at the National, downing Rob Rumfeldt 7-1 in seven ends. The loss dropped Rumfeldt's Guelph, Ont., team to 0-3. Ulsrud, from Oslo, Norway, is 1-2.