Middlesbrough 0 Arsenal 4The industrial chimneys and the ritual references to the locals as smog monsters will prevent Middlesbrough from ever being regarded as a spa town, but it is the place where Arsenal come to feel good about themselves. Even in April, when the falling masonry of a fractured season smashed down on them, Arsene Wenger's team could tend their wounds at the Riverside as Thierry Henry's free-kick secured a 2-0 win.

In the already burgeoning hope of August, this was still a therapeutic visit to their favourite health farm.

Middlesbrough, sticking with a back three for the hapless opening 23 minutes, might almost have been trying to highlight the deadly acuteness with which the Highbury side can break on the flanks.

The goals were fun for Wenger's men and, in a period when the Arsenal defence is under stern review, it must have been agreeable to keep a clean sheet at this stadium for a fourth consecutive Premiership win. That satisfaction will be particularly fleeting, though, because of the sheer inadequacy of the opposition, who are beset by injuries. Arsenal should be heartened far more by the impression that valuable individuals are regaining their full powers.

Nowadays footballers are both fitter and, in their finely tuned condition, more vulnerable. Fortunes are swayed by medical matters as much as by the drama of games. The slight decline of Arsenal from the Double season was, in part, bound up with the travails of Robert Pires and Freddie Ljungberg. After missing the 2002 World Cup because of knee surgery the Frenchman was soon back in action but that type of speedy return to the fray is deceptive. Pires's gifts were still apparent, but the overall effect was never quite the same. The run and controlled low shot into the corner of the Bolton net in the spring was one of the few clues that he could eventually be comfortable in his superiority once again. Yesterday Pires revelled in his mastery.

Ljungberg will never be as refined a character and, in the wake of his hip injury, there were supporters who felt Wenger should offload him if it was necessary to do some trading in the transfer market. Arsenal, though, need the liveliness with which the midfielder can get himself into the critical areas and claim important goals.

He was not on the scoresheet yesterday, but the trademark energy was there as he received Sol Cambell's pass and drove into the penalty before squaring for Sylvain Wiltord to put Arsenal 4-0 ahead. By the 74th minute a contented Wenger had gathered all the evidence he required, with Ljungberg and Pires among the three men replaced. The Swede had been frisky from the beginning, bounding on to Patrick Vieira's immaculate pass after six minutes and hitting the shot that Mark Schwarzer's one-handed save could only turn into the path of Henry for the opener.

It was the intelligence and craftsmanship of Pires, though, that dominated the day. When Ashley Cole fed him on the left in the 13th minute, he worked the ball on to his right and dropped it into the path of Gilberto Silva for the Brazilian to volley his first Premiership goal.

The flexibility of Pires's talent makes him dangerous in a wide range of different situations. He was well inside his own half when taking control in the 23rd minute to launch the kind of Arsenal counter-attack that is utterly predictable and equally unstoppable when the opposition leave themselves as exposed as Middlesbrough. Henry peeled off to the left and Pires placed the ball perfectly in his path. Wiltord then flicked in the cut-back.

Middlesbrough, having conceded seven goals in their first two Premiership fixtures, will prefer to regard this as an occasion when, due to circumstances, a bright future had to be postponed. Gaizka Mendieta, with his international clearance yet to arrive, was only on the field to wave to the crowd beforehand.

He was joined there by Danny Mills and while the loan signing of the Leeds United right-back will not inspire mania on Teesside, the introduction of any new defender should be welcome. Apprehensive around their own penalty area and outclassed in midfield, Middlesbrough were excruciatingly short of substance here.

Juninho, with all his artistry, could readily have been pardoned if he had detached himself from a display of such shoddiness. Luckily for Middlesbrough, the Brazilian is no prima donna and he applied his flair diligently even if his reward was paltry when he forced Jens Lehmann's one genuine save.

The Middlesbrough manager Steve McClaren must be exasperated by his captain Gareth Southgate's talk of wanting to move to a prestigious club. It may not be the kind of assignment he seeks, but there is a big enough challenge for the centre-half and his team-mates at the Riverside.