Duran has scored six goals in five matches for Martin O'Neill's side after his latest eye-catching contribution at Parkhead.
The Colombian netted in the 14th minute with the latest in his series of spectacular strikes since joining from Qarabag in the close-season.
Duran collected Benjamin Nygren's pass and unleashed a long-range drive that cannoned in off the crossbar.
"He's a terrific player. He has set the tone for us since the beginning of the season," O'Neill said of Duran.
"He's playing in a position which is really strong for him but he can play in a number of positions, he's that good."
Nygren and Yang Hyun-jun were also on target as Celtic killed off the game before the break.
Although they suffered a humiliating Champions League exit against LASK, Celtic have made a perfect start to their title defence with four successive wins.
"We played very well. We seemed to control the game for the most part and I thought the first goal was a big moment because the game was still in the balance," O'Neill said.
"Overall, I'm just delighted with the win, the goals we scored, and pretty pleased with the display."
It was an emotional night in Glasgow as Kenny Dalglish was given a warm ovation on the pitch before the match.
Dalglish launched his iconic career with Celtic before joining Liverpool in 1977.
The 75-year-old revealed earlier this year that he was receiving treatment for cancer.
Nervy Rangers win
Celtic are two points clear of second-place St Mirren, whose 1-0 win at Kilmarnock was secured by Fraser Taylor's maiden goal for the club in the third minute.
St Mirren's first victory at Kilmarnock for 13 years kept them three points ahead of fifth-placed Rangers.
Lawrence Shankland's double gave Rangers a dramatic 2-1 win over Falkirk to ease the pressure on boss Derek McInnes.
With McInnes serving the first of a two-match touchline ban for comments made as Hearts manager last season, he watched from the stands as Rangers striker Shankland saved him from another chastening result.
Shankland, who scored from the spot in the 1-0 win at Aberdeen on Sunday, fired Rangers ahead with a fine strike in the seventh minute.
Kosta Nedeljkovic, making his first Rangers start since signing on loan from Aston Villa, turned an Ethan Ross cross into his own net to give Falkirk an unexpected equaliser just before the break.
But Scotland star Shankland, who signed from Hearts in the close-season, reduced Rangers' anxiety when he curled in the winner after 79 minutes.
"We knew coming here it was going be another difficult task, but the important thing was to follow up the win at the weekend and come away with three points. We've managed to do that," Shankland said.
Motherwell are third after Seb Palmer-Houlden, Alex Lowry and Dylan Levitt scored their first goals for the club in a 3-0 win against Dundee United.