AMHERST, N.S. -- Bill Casey returned to politics in Nova Scotia at age 70 to send a message to Stephen Harper, but his victory in what was seen as a key riding for the Liberals was overshadowed by the party's victory in all 11 ridings in the province.

Casey, a former Conservative, decisively won the race against incumbent Scott Armstrong in Cumberland-Colchester as the Liberals picked up four ridings that had been Conservative strongholds for decades in Nova Scotia.

The Liberals also swept aside high-profile New Democrats Megan Leslie, Peter Stoffer and Robert Chisholm, as the NDP's urban base appeared to crumble against the Liberal wave that moved across Atlantic Canada.

"It is a strong message, not only here but across Atlantic Canada that the people want change, and they're going to get it," Casey said during his acceptance speech to party supporters at pub in Amherst.

Casey became a folk hero in Nova Scotia when he was expelled from Harper's caucus in 2007 after he voted against the party's budget, saying it would hurt Nova Scotia's offshore oil and gas industry. His decision to defy Harper earned him a reputation as a regional champion, helping him win the riding in a landslide as an Independent in 2008 before stepping down as he recovered from cancer.

His supporters chanted "No more Harper" during the party celebration.

"You may have noticed that on our signs we have, 'Send Stephen Harper a message,' and I think we did send him a message," said Casey.

His win was part of a wider Liberal success story in the province.

In Central Nova, Liberal Sean Fraser won the seat previously held by Peter MacKay, the justice minister who decided not to seek re-election this time. Fraser beat Tory candidate Fred DeLorey.

Political scientists had described the Central Nova seat as a family dynasty, as constituents who voted for Elmer MacKay seemed content to shift their loyalty to his son when the younger MacKay first ran in 1997.

It was also a difficult night for the New Democrats.

In Dartmouth-Cole Harbour, Chisholm lost his seat to Liberal challenger Darren Fisher.

The results in Halifax saw Leslie, a deputy leader of the NDP, lose to Liberal Andy Fillmore. The New Democrats had held the riding for almost 20 years.

Stoffer, a popular MP, finished second in Sackville-Preston-Chezzetcook to Liberal Darrell Samson.

Meanwhile, on the province's south shore, the departure of Conservative MPs Gerald Keddy and Greg Kerr from politics before the election also created openings for Justin Trudeau's campaign. The Liberals won both south shore seats.

In Cape Breton, Liberal MPs Mark Eyking and Roger Cuzner both cruised to early victories in their ridings, as did Geoff Regan in Halifax West and Scott Brison in Kings-Hants.

The recent political history of the province has seen all of the parties go through cycles of rapid rise and fall.

The Liberals last swept Nova Scotia in 1993, when they took all 11 seats as Jean Chretien won his victory over Kim Campbell.

The New Democrats have won seats in the province over the past decade, and began the race hoping to make gains in rural areas while holding their strength in Halifax and the suburb of Dartmouth.

Armstrong said the size of his defeat to Casey was partly due to a nosedive in the New Democrat vote across the region.

"The collapse of the NDP was significant," he said by telephone from his headquarters in Truro. "When the NDP vote totally collapses it makes it very difficult for us to win here."