Owen struck a 97th-minute winner to see off Coventry City, who had fought back from two goals down to take the game into extra time, and book Newcastle's place in the third round.

United played some superb football on their first visit to the Ricoh Arena, and had stormed into a 2-0 lead by the 38th minute thanks to an own goal from Scott Dann and a strike from James Milner.

But Clinton Morrison pulled one back in first-half injury-time, and Dann levelled the scores four minutes into second-half stoppage time, despite referee Tony Bates only signalling two minutes of added time.

And it took a clinical strike from Owen - who had scored the only goal of the game against Bolton Wanderers at St James's Park on Saturday - to decide the second-round tie in United's favour.

Keegan had made three changes from the side which beat Bolton Wanderers 1-0 thanks to an Owen goal on Saturday, with Sebastien Bassong, Geremi and Jose Enrique coming in for Damien Duff, Obafemi Martins and Steven Taylor.

Bassong made competitive debut for the club in the centre of defence alongside his fellow new signing Fabricio Coloccini after his summer move from Metz.

Owen was named on the bench, with Keegan feeling the striker was not yet ready to start a game so soon after his return.

Also among the substitutes was 17-year-old striker Nile Ranger, who has joined Newcastle's Academy from Southampton.

United's first real chance of the game fell to Coloccini, who shot well wide after a corner ball was eventually worked to him just outside the box in the 11th minute.

A minute later Charles N'Zogbia - restored to his favoured wide left role in midfield - sent a 25-yard free kick well over Andy Marshall's goal.

Keegan gave Newcastle's 2,000-plus fans a wave as the quarter of an hour mark passed, and the club's vociferous travelling supporters were getting behind their team in the early stages of the game.

With 20 minutes on the clock Bassong did well to take the ball off Michael Mifsud - who faced Newcastle in the colours of Lillestrom in an Intertoto Cup match two seasons ago - on the edge of the box.

And within a minute United themselves were ahead thanks to N'Zogbia, who got prodded Milner's low, left-wing cross past Marshall with the help of Scott Dann to open the scoring.

Keegan's men then seized control of the game, with Coventry unable to get hold of the ball.

Milner shot wide in the 28th minute as Newcastle built up a head of steam going forward, and the winger had another effort, this time goalbound, well blocked by Dann just past the half hour mark. Seconds later, he was again denied a goal, this time by Danny Fox.

However, Milner couldn't be denied for too much long, and he made it 2-0 in the 38th minute when his left-wing cross-cum-shot awkwardly bounced past Marshall and into the far corner.

United had dominated the first 45 minutes, but the suffered a blow on the stroke of half-time when Morrison halved the deficit with a first-time effort after the ball rebounded off Bassong and to his feet just outside the box.

It was tough on Newcastle, but Keegan's side - captained by midfielder Nicky Butt - started the second-half well, piling more pressure on Colemen's men.

However, United didn't have it all their own way, and as long as the visitors didn't extend their lead again, there was hope for the Sky Blues, owned by former Newcastle defender Ray Ranson.

Owen finally made it on to the pitch with 15 minutes left on the clock, with Keegan having been wary of throwing him on too early with a gruelling period of extra time still a possibility.

And that became a reality deep in injury time, when Dann headed home from close range after Aron Gunnarsson had sent a powerful long throw into the box.

The home supporters got behind their team as extra-time started, with Newcastle's fans at the other end still coming to terms with a comeback from City which few had seen coming.

Seven minutes into the first period United were ahead thanks to Owen, who latched on to Enrique's ball forward to coolly finish past Marshall and send the visitors into a 3-2 lead.

The goal - the 22nd of Owen's St James's Park career - also brought the away end back to life.

Coventry's Elliott Ward struck the bar in stoppage time at the end of the period to set up a grandstand finale.

However, Coventry could not summon another late goal, and United held on to win the game.

COVENTRY CITY: Marshall; Hall, Ward, Dann, Fox; Mifsud, Beuzelin (Doyle, 63), Gunnarsson, Tabb (Simpson, 89), McKenzie (Gray, 74); Morrison. Subs not used: Ireland, Turner, Thornton, Clarke.

NEWCASTLE UNITED: Given; Beye, Bassong, Coloccini, Enrique; Geremi (Owen, 75), Guthrie, Butt, N'Zogbia; Gutierrez, Milner. Subs not used: Harper, Edgar, Taylor, Tozer, Donaldson, Ranger.

Goals: Dann og 21, Milner 38, Morrison 45, Dann 90, Owen 97

Bookings: Hall 66, Fox 86

Sent off: None

Referee: Tony Bates (Stoke)

Attendance: 19,249