It seemed crazy for Arsène Wenger to keep playing Jack Wilshere, the kid who spent 17 months out injured, the boy who has not stopped chasing and coaxing and creating since he stepped back on to the pitch in October. Rest Wilshere? Who has started nine games in a row? No chance. He has become the heartbeat of Arsenal – the conductor, the driving force, the de facto leader.

Having pushed his team on against Swansea City with a compelling blend of energy and imagination, he capped his performance with an emphatic matchwinner four minutes from the end to earn Arsenal a fourth-round tie at Brighton and Hove Albion. "I'll never hit one like that again in my life," he said, after striking the decisive goal past Michel Vorm.

It was fitting that Wilshere defined the result because he had demonstrated a relish to take charge that stood out a mile. His commitment, his involvement, over recent weeks had convinced Wenger to position him in the role he flourished in throughout the youth teams, with the No10 on his back. He was positioned in the advanced playmaker role and, as he grew into the game, it was something Swansea could not handle. "He was outstanding," observed Wenger. "He played in a different position tonight, a bit higher up. It suits him well." His true position? "I think he is a complete midfielder," Wenger said, a little cautiously.

In fairness to Michael Laudrup's team, who have been so enterprising this season, with six changes to give a few of their key performers a breather it was difficult to sustain their composure as a full-strength Arsenal began to crank up the pressure.

The first half had been even. Swansea were as much of a threat as Arsenal and came close to taking the lead when Kyle Bartley ghosted in to rattle the bar. The temperature was raised in the second half, however, as Swansea suddenly found themselves on the ropes, trying to resist a red and white swarm. Arsenal forced 26 attempts on goal.

They found an interesting balance to their game. With Francis Coquelin and Abou Diaby forming a more robust midfield base, and Olivier Giroud a handful up front even if he blundered in front of goal, Wilshere, with the pace of Theo Walcott and the guile of Santi Cazorla either side of him, pulled the strings with great dynamism.

Swansea's defending was astounding at times, with last-ditch clearances that had Wenger wondering how it was possible for the game to be goalless for so long. Laudrup described his players' efforts as "heroic". Leon Britton and Danny Graham did as much as any authentic defender to clear the decks, Dwight Tiendalli stepped in with an astonishing double interception, and Vorm flung out arms and legs to keep Swansea in it. It was engrossing. The only respite came from Ki Sung-yueng's drive but Wojciech Szczesny kept his wits about him to tip aside the danger. There was some anxiety when Laudrup introduced Michu but this time the Spaniard was unable to make an impact.

Wilshere would deal the devastating blow. After a neat exchange with Giroud the ball sat invitingly. With a swipe of his left foot he powered it past Vorm to send Arsenal into the next round.

It was pertinent to hear Laudrup, who has substantial personal experience of the world of the young prodigy, try to temper his praise of Wilshere with caution. "I think sometimes people are a little too fast, too quick with the big words," he said, urging people to give him time and space to develop into a better player, and arguing it is too early to use the term "world-class".

On matters closer to home Laudrup had no complaints. "In general when you play a game and the opponent, like here in one half, are better than you, they deserve to win," he assessed, before adding that the challenges are coming thick and fast. "We just have to continue. We have a trip back, arrive back at 2am and on Saturday we play Stoke at home. Then we play Wednesday in that game that the whole of Swansea is thinking about, which is the second game of the League Cup semi-final [against Chelsea]."

For Arsenal Wenger suggested that it was more than just the FA Cup at stake. The strength of his cup teams indicates he is feeling the pressure to deliver trophies but the Arsenal manager claimed the urge to respond to a sobering defeat against Manchester City was just as important. He needed his strongest possible team and his strongest player.