IPSWICH: Richard Wright, Rosenior, Bruce (Smith 39),Balkestein, Delaney (Peters 60), Walters, Trotter, Colback, Leadbitter, Edwards, Priskin (Counago 61).Subs Not Used: Lee-Barrett, Martin, Stead, Quinn.
TOON: Harper, Steven Taylor, Khizanishvili, Coloccini (Lovenkrands 68), Jose Enrique, Smith, Nolan, Butt, Ryan Taylor (Donaldson 78), Carroll, Ranger (Harewood 65).
Subs Not Used: Krul, Ngo Baheng, Tozer, Vuckic.
Att: 27,059
The Magpies hit three goals in four first-half minutes to crush Keane's disillusioned side - who have now made the Suffolk club's worst ever start to a season - on an emotional afternoon at Portman Road.
Both sets of fans paid tribute to the late Sir Bobby Robson throughout as Ipswich renamed a stand in honour of their former manager, who died in July.
But while Ipswich have now made it nine league games without a win, Newcastle - where Robson ended his illustrious managerial career - have made light of their relegation from the Barclays Premier League in May with an impressive start.
They dominated from the off and opened the scoring with an excellent Nolan header before the former Bolton captain scored again 60 seconds later.
Ryan Taylor then drove home a free-kick for Chris Hughton's side before Nolan completed the rout after the break.
Newcastle captain Alan Smith set the tone with two crunching tackles in the opening 90 seconds and the visitors came close to an opening goal in the fifth minute.
Nolan played the ball up to Nile Ranger, who showed superb strength to turn Alex Bruce on the edge of the area.
The 18-year-old then had the poise to dummy inside the challenge of Liam Rosenior and get a shot away, which goalkeeper Richard Wright did well to palm behind for a corner.
The visitors were playing all the football, with the experienced trio of Smith, Nicky Butt and Nolan controlling proceedings in midfield as Ipswich looked woefully short of confidence after their disastrous start to the season.
Nolan looked a class above and opened the scoring with a marvellous header in the 30th minute.
Jon Walters gave away a silly free-kick for a push on Ryan Taylor on the right wing and, from the former Wigan man's delivery, Nolan leapt high to power a header past Wright and into the roof of the net.
The away fans had hardly stopped celebrating when Nolan grabbed his second a minute later.
Andy Carroll played the ball over the top for Nolan, who surged into the area. He easily cut inside a flimsy challenge from Pim Balkestein and slipped the ball between Wright and the near post for a tidy finish.
Newcastle were rampant and went 3-0 up in the 34th minute.
Ranger was fouled on the left-hand side and Taylor stepped up to curl a fine 25-yard free-kick over the wall and into the top corner.
A parade of Robson's former Ipswich players entered the field during half-time, including Scotland and former Tractor Boys manager George Burley, as the FA Cup and UEFA Cup won under the former England manager were rightly celebrated.
The current crop made a slightly better start to the second period, with Walters heading onto the roof of the goal, but Nolan soon completed his treble in the 50th minute.
Zurab Khizanishvili charged down the right wing before laying the ball off to Ryan Taylor. He picked out Ranger unmarked at the back post and his header back across goal looked like finding the net until Nolan arrived to nod over the line from three yards out.
The visitors saw out the rest of the game with ease and gave a debut to on-loan Aston Villa forward Marlon Harewood in the closing stages.
Attention now turns to Keane's immediate future as the former Manchester United captain reflects on the fact that, after nine games of a season which promised much, his side are only being kept off the bottom of the division by Plymouth.