The 34-year-old rifled his first Bournemouth goal in 16 years, as the Cherries came from behind to sink visitors Brighton 2-1.
Solly March’s header had Brighton dreaming of a second successive Premier League win but Andrew Surman coolly levelled before England poacher Defoe stole the victory.
Defoe last scored for Bournemouth on a loan spell in May 2001, and the veteran exhibited all his stunning staying power to settle this south coast derby.
Bournemouth were in real danger of losing five successive Premier League matches for the first time when March capped a flowing move, but manager Howe’s men responded in style to kick-start their season.
Defoe has turned out for West Ham, Tottenham, Portsmouth, Toronto FC and Sunderland since his loan stint on the south coast as a teenage goalscorer of rich promise.
A full generation of strikers has come and gone in between, but still Defoe keeps on delivering, adding again to his impressive haul that included 15 Premier League goals with the Black Cats last term.
The Cherries’ success leaves Crystal Palace as the final top-flight team still seeking points, with Defoe securing a crucial boost to boss Howe.
EPL Table | Premier League 2017-18 season table
Roy Hodgson takes charge of his first game as Crystal Palace manager on Saturday as the Eagles – rock bottom of the table – host Southampton at Selhurst Park.
There’s a host of action for the regular 3pm kick-offs to follow, with West Brom hosting West Ham, Burnley seeking another away shock at Liverpool, and Manchester City aiming to keep up their title ambitions with a trip to Watford.
Saturday’s late kick-off sees Tottenham looking for that first Wembley League win of the season against Swansea before a big Sunday of action.