Arsenal punishes sorry Newcastle
Wenger had talked up Walcott as the next Thierry Henry on Friday, and the England forward - still to pen a new deal with the club - did little to disprove that idea on Saturday, scoring three excellent goals and setting up two more to give Arsenal the win that ensures they will end 2012 in fifth place, two points behind Chelsea and three adrift of Tottenham with a match in hand.
Arsenal's record scorer Henry was in the stands watching his beloved former club and he was on his feet after 20 minutes thanks to Walcott's opener - a fine curled finish following an Henry-esque break from the halfway line.
Newcastle pulled level through Demba Ba, but Alex Oxlade-Chamberlain scored, only for Ba to grab his second to make it 2-2.
Arsenal looked set for a disappointing draw after Sylvain Marveaux equalized Lukasz Podolski's header, but Walcott turned on the class to put the Gunners 4-3 up.
The former Southampton man set up Olivier Giroud twice and added his much-deserved third strike in injury time with a deft chip over Tim Krul.
Walcott has scored four goals and won one decisive penalty in the three games he has started up front and he now has 14 for the season.
There were no early indications that this would turn out to be a thriller in the opening quarter as both teams started sluggishly.
Other than a couple of bits of skill from Santi Cazorla, Arsenal started poorly.
Walcott, eager to show he can cut it as a striker, used his pace to break behind the Newcastle defense, but Krul rushed off his line to clear.
Newcastle, branded a "wee club in the north-east" by Sir Alex Ferguson on Friday, had the best chance of the opening quarter of an hour through Ba who somehow headed over Marveaux's corner from eight yards.
The quiet atmosphere inside the Emirates Stadium lifted after 19 minutes when Podolski slotted Walcott in behind the Magpies defense and the England man raced through before caressing the ball past Krul in to the far corner.
The goal was reminiscent of many strikes from Henry and thus brought the Frenchman to his feet in the stands.
Walcott was in the thick of the action again just before half-time, wriggling free from his marker, but Krul came off his line to stop the 23-year-old's shot.
Cheick Tiote, who scored the equalizer in February's 4-4 thriller, almost brought the visitors level six minutes before the break with a swirling 25-yard drive that Wojciech Szczesny awkwardly punched away.
Walcott immediately flew up the other end, but he laid a square pass behind the un-marked Cazorla, rather than in front of him and Gael Bigirimana cut the danger out.
Arsenal were made to pay for the error just over two minutes from the break.
Bacary Sagna fouled Gabriel Obertan 25 yards out and Ba's resulting set-piece flew off Jack Wilshere's head in to the Arsenal goal past the stranded Szczesny.
Arsenal came out much stronger after the break. Kieran Gibbs drew a save from Krul at his near post shortly before Oxlade-Chamberlain beat the Dutchman to make it 2-1.
Podolski intercepted a weak throw-in, heading the ball to Cazorla, who found Oxlade-Chamberlain and he made no mistake with a fine low drive from 20 yards.
Walcott somehow muscled Tiote off the ball and charged at goal, but he dragged his shot horribly wide.
Once again Arsenal were made to pay as Newcastle equalized. Obertan turned Sagna inside out before his cross was deflected off Koscielny and in to the path of the un-marked Marveaux who tapped in to an empty net from barely two yards.
Arsenal were back ahead within five minutes, however. Wilshere charged at the Newcastle defense and chipped a wonderful ball to the back post. Coloccini could only head his clearance against the bar and the ball fell to Podolski who nodded home the easiest finish of his career to make it 3-2.
The 60,000 fans inside the Emirates Stadium barely had time to draw breath before Newcastle equalized again.
Marveaux bought time with his trickery before swinging a ball to the back post where Ba bustled Gibbs out of the way to turn the ball past Szczesny.
The home crowd blasted their team's sloppy defending, but Walcott dug them out of trouble five minutes later with Arsenal's fourth.
Gibbs slotted the ball across the box for Podolski, he missed ball, but Walcott was stood just behind him and he fired in to the roof of Krul's goal. Giroud then killed off the game with five minutes left, latching on to Walcott's cross to head between Krul's legs.
The Frenchman then rubbed salt in to Newcastle's wounds by slotting past Krul to make it 6-3 after Walcott charged at the Toon defense. Walcott then got the hat-trick he deserved in injury time, picking himself off the turf after being flattened by Tiote before chipping the ball over Krul with a brilliant finish.
Arsenal could have had an eighth in injury time, but Giroud's header hit the bar. Walcott, wearing a beaming smile, walked off with the match-ball amid chants of "sign him up" from the home crowd.