When the fixtures tumbled out of the computer for the start of a newly promoted season, Nigel Adkins must have wondered whether he had unknowingly broken any mirrors while walking under a ladder. Hot on the heels of a tough introduction to both Manchester clubs, a rampant Arsenal lacerated Southampton.

It was as comfortable an afternoon as Arsène Wenger could have wished for in a situation that can be tricky in between internationals and the upcoming Champions League. The Frenchman was even able to experiment with his forward line. The most notable aspect was not so much the absence of Olivier Giroud, who Wenger felt needed a break from the pressure, but the identity of his replacement as the team's spearhead: Gervinho.

The Ivorian is a player with such a liking for improvisation it does not usually look like he has any more idea than anyone else what he is going to do next, so it was an interesting choice. As it turned out, it was a masterstroke. The striker was full of running, played with a more direct shoot-on-sight approach than normal and finished with two goals and an assist.

"We transform all wingers into strikers," Wenger said with a sparkle in his eye. The seed had been planted on the pre-season tour of Asia. "I decided to try it. He's such a great mover, so quick, and once he's ahead of the last defender it is difficult to catch him. I hesitated about whether to play him or [Lukas] Podolski, who gives us balance on the left and I didn't want to destroy that."

With good reason. In the 11th minute the German won possession in midfield and teed up the galloping Kieran Gibbs, whose angled shot was pushed by Kelvin Davies straight into the retreating Jos Hooiveld. The Dutchman could not avoid poking the ball over his own goalline.

Arsenal's dominance was reflected in a flurry of goals before half-time – three in six minutes: first, Podolski turned the screw with a peach of a free-kick; then Gervinho accelerated on to Mikel Arteta's beautifully crafted pass and beat Davis at his near post with conviction; and finally Southampton's defence unspooled completely when Gervinho broke to release Gibbs, whose return ball cannoned off Nathaniel Clyne for Southampton's second own goal of a sobering afternoon. Adkins looked shell-shocked in his dugout. "They were ruthless," he said later.

In the spirit of gifts, Wojciech Szczesny provided a glimmer for Southampton with a sloppy claw at Jason Puncheon's cross, allowing Daniel Fox to break Arsenal's run of clean sheets. Asked if Szczesny was disappointed with himself, Wenger's expression spoke volumes.

While there was hardly an air of panic, a collective intake of breath was heard when Rickie Lambert glimpsed the opportunity to take aim; Southampton's hitman drilled wide. The visitors were a little more bullish in the second half and welcomed Gastón Ramírez, although they lacked the guile to fashion many clear-cut chances.

Adkins was pleased with his debutants even though they came on in difficult circumstances. It was particularly challenging for the Japanese defender Maya Yoshida, who replaced the injured Hooiveld early on. "Maya was in at the deep end," the Southampton manager said. "He only had one training session with us and he grew into the game. And you can see what a quality footballer Gastón Ramírez is going to be for this football club. You find out about people when you are up against the wall. James Ward-Prowse was outstanding as he kept going and kept trying to play."

It helped that Arsenal eased off slightly, if not entirely. The fifth came when Santi Cazorla – exceptional again as the team's conductor – released Aaron Ramsey, who carved out an opening with clever footwork. His dinked effort drifted on to the post and that man Gervinho was in the right place to nudge the rebound over the line. The former Saint Theo Walcott curled in the sixth after Thomas Vermaelen stormed upfield to test Davis.

When they were finally put out of their misery, Walcott and the other kid nurtured at St Mary's, Alex Oxlade-Chamberlain, made a point of going to salute the visiting supporters. Bottom of the table and on the end of a pummelling, the nostalgic gesture was well received but a minor consolation. "When the fixtures came out people thought we'd get a right good chasing," Adkins said. "We have had a conversation in the dressing room. We've got the belief we can play in this division. We will have a great week's training and I'm sure St Mary's will be bouncing next weekend."

As for the home crowd, the mood contrasted sharply with the last time they were here – a sluggish goalless draw against Sunderland on the first day of the season. Improvements since then have bred optimism, but Arsenal will have a much greater idea of how they are shaping up next weekend when they travel to Manchester City. "We are a team with a big positive energy but we have two interesting weeks, with Montpellier, City and then Chelsea," Wenger said.