There was a sense of inevitability about the 227th goal when it came. Thierry Henry had been feeling his way into his second coming at Arsenal, finding rhythm on the periphery, when he glided silently away from Zac Thompson, collected Alex Song's pass and skimmed his shot beyond Andy Lonergan and into the far corner. A hero had returned home but, in witnessing the delirious chest-thumping celebrations that followed, it felt as if the Frenchman had never been away.

As eye-catching returns go, this took the breath away. As player and manager later acknowledged, it was simply the stuff of dreams. When Ian Botham returned from a drug ban to the England team at The Oval back in 1986 and enticed a mesmerised Bruce Edgar to nick the all-rounder's first delivery to Graham Gooch at slip, drawing him level with Dennis Lillee's then record Test haul of 355 wickets in the process, the catcher had meandered up to the celebratory huddle to ask: "Who writes your script?" Wenger might have been muttering the same in his compatriot's ear once he had extricated himself from the bear hug on the touchline. Henry still has the timing of a genius.

Even he was incredulous both to have registered with only his fifth touch and also to have claimed the sponsors' man of the match for a 21-minute cameo. He had actually topped that poll, voted for by television viewers, while still prowling the touchline as an unused substitute. "A joke," he said with a sigh and doubting shake of the head, even if the smile plastered across his face said more. The player could never have envisaged an occasion such as this when he returned from a holiday in Mexico a fortnight ago. He had stood arms aloft at the final whistle staring to the heavens as if wondering whether any of this was actually real. Scoring the winning goal had apparently cost the bookies over £1m.

It is almost five years since he had limped away from this stage, hamstrung as his team-mates exited the Champions League to PSV Eindhoven, as an Arsenal player. His game had already been adapting towards the end of his glittering first stint in north London, the spearhead of a team who had been Invincibles for a campaign. The process of adjustment had continued at Barcelona before New York Red Bulls lured him for a swansong in Major League Soccer. He had returned with a nod of acknowledgment to the passing of time and an insistence that he should not be considered "a hero". That hope has already been jettisoned.

The home fans revelled in his restoration to the ranks. This had been a largely drab occasion, Leeds' admirable industry and endeavour threatening to earn them a replay as they had in this competition a year ago. It needed the drama of Henry's involvement to illuminate proceedings. The home support's bellowing of his name had confirmed as much, their reaction ecstatic when the veteran, with a pat on the head from the departing Marouane Chamakh, entered the fray. His first involvement was to wander offside but he was soon dragging opponents out of position. He may not be blessed with the jet-propelled pace of old but his reputation remains. The goal which followed nine minutes after his introduction ignited the night.

Henry will offer plenty in what is likely to become an eight-week sojourn in familiar surroundings. He retains a poise and presence on the pitch that will have opposing defenders shrinking. The strut was in evidence aplenty even last night, when there were only flashes of his truest touches. But his attitude alone should have a positive effect on this young squad. Only Song of those who started had previously played alongside Henry in the Arsenal first team. Others will learn from his mere presence. "I can definitely have some input out there, to talk to the guys and let them know what it means to win," he had said. "I am a competitor and that will never leave my body."

Chip in with goals of this quality while Gervinho and Chamakh – neither of whom has proved prolific – are at the Africa Cup of Nations and some of the pressure placed on Robin van Persie will be alleviated. "I am not 25 any more," Henry had said. "I am not going to take the ball from the middle of the park and dribble past five or six players." But the comparisons are inevitable and, even after this taster, they still feel appropriate.

Tougher opponents than Leeds await and he should still be around when Arsenal play Manchester United and even Tottenham Hotspur. But this is a player who continues to hog the limelight. He writes his own script.