© Getty Images
Their three points over the relegation-threatened Tangerines mean that Sean Dyche's men will go up if Derby County fail to beat Doncaster Rovers this evening.
Kightly's 49th-minute goal was of top-flight standard, a 20-yard curling effort following a one-two with Dean Marney, but Kieran Trippier's stoppage-time clearance off the line was just as important for the second-placed Clarets on a day where Blackpool's off-field problems surfaced again.
Twenty-goal striker Danny Ings was another who miscued from a good position, shooting into the ground and straight at Gilks, who was more severely tested by the forward from Ashley Barnes's 30th-minute cross.
Blackpool, who have now lost four consecutive games, were forced to play Neal Bishop as a makeshift frontman due to several injuries, and thus rarely looked dangerous going forward during the first period.
They continued to be unthreatening after the break, but another promising opportunity fell to Burnley, with centre-back Michael Duff slicing wide from eight yards after a corner had been rolled into his path.
Only two minutes later, Burnley's superiority was rewarded as Kightly found the feet of Marney before running inside to lose his marker, collect the return and bend a left-footed shot inside the far post.
Play was temporarily suspended after the goal when Tangerines fans threw hundreds of tennis balls onto the pitch in protest of chairman Karl Oyston's running of the club during their plummet down the table.
It took until the 94th minute for Blackpool to register a shot on target, and Andy Halliday's volley looked bound for the top corner before Trippier leapt to head the ball away from danger.
The right-back's late act of heroism was the highlight of another organised and brave defensive display from the Turf Moor outfit, whose 35 goals conceded this season is the best record in the division.
Burnley are now 11 points clear of Derby and will be uncatchable if the Rams drop points at the Keepmoat Stadium, while Blackpool are just two points above the Championship relegation zone.