Arsene Wenger's charges were at their free-flowing best, the perfect tonic to the disappointment of last week's defeat to Fulham.
Newcastle arrived at the Emirates Stadium hopeful of topping the table with a victory over under-pressure Arsenal, but the Gunners were reading from a different script.
Within seconds of the opening whistle the Gunners had a good claim for a penalty when Robin Van Persie was hacked down on two minutes. William Gallas should have made sure just 60 seconds later when he met a Robin Van Persie cross from just six yards out, but his right-foot shot flew high over the bar.
The Gunners did however take the lead after 17 minutes when Charles N'Zogbia handled inside the area. Up stepped Van Persie to drill the spot-kick left-footed into the right side of the goal.
The goal gave Arsenal the confidence boost they needed to slot into their free-flowing football to keep the visitors pegged back. Cesc Fabregas, starting his first league game of the season, was beginning to find his passing range. Van Persie was usually the target as the Dutchman terrorised Keegan's side.
Samir Nasri was also making a nuisance of himself on the left flank, running at will at the flat-footed and bemused Newcastle defence. In one such move the Frenchman found the Dutch striker, who danced his way past three defenders before being hauled down.
Van Persie sent a goalbound free-kick toward the top left corner, but Shay Given somehow stretched every sinew to keep the ball out.
Michael Owen should have levelled the scores on 37 minutes when teed up in front of goal, but the England striker pulled his shot wide from just 12 yards out.
The Gunners looked certain of doubling their lead a minute later when Emmanuel Adebayor had possession in front of goal, but somehow dragged his effort wide of the left post when it would have been easier to score.
The second goal did eventually come on 41 minutes following a slick move that began on the right flank with Adebayor, who fed Emmanuel Eboue running in behind.
The Ivorian midfielder cleverly back-heeled the ball towards Van Persie, who ran into the box and fired into the roof of the net with his right foot.
Arsenal had Manuel Almunia to thank in first-half injury time when the Spanish keeper tipped over Owen's looping header in spectacular fashion.
Newcastle went close on 56 minutes when Nicky Butt's backwards flicked header from N'Zogbia's corner to the near post looped over Almunia but cannoned off the top of the Gunners bar.
Almunia was called into action just seconds later when he dived to his right to gather Danny Guthrie's 20-yard drive.
The Gunners went 3-0 up on 59 minutes when Denilson finished a clever move that was begun by Nasri, who intelligently found the youngster who swapped passes with Adebayor before directing his shot past a flat-footed Given.
Van Persie almost completed his hat-trick in fabulous fashion when his left-foot shot from the acutest of angle hit the underside of the bar before bouncing away to safety. That was the last kick of the game for the Dutchman who injured himself in the process.
Gael Clichy tested Given with a curling 25-yard effort in the 70th minute, but the Newcastle keeper kept a keen eye on the viciously swerving ball.
Given was again in the right place at the right time to block Kolo Toure's close-range headed effort as the Gunners looked to add to their tally.
Given was being worked hard by the Gunners, but he was up to the task in a busy period around the 80th minute when he saved Nasri's curling free-kick and then denied the lively Carlos Vela twice from close range.
Theo Walcott should have made it 4-0 in the 86th minute after being set up by Adebayor, but he fired his shot wide of the right post under pressure from Given.