Arsenal 2 West Brom 0

It falls to an Arsenal member of staff to walk through the press box at half-time with a sheet of A4 paper bearing the official attendance. He often does so with an apologetic sort of demeanour and it was more pronounced than usual here. The number read 59,568. In other words, the Emirates Stadium was practically sold out.

The figure is based on tickets sold, remember, rather than the number of fans who pass through the turnstiles. The reality was that there were at least five or six thousand no-shows, as Arsenal’s season limped towards its conclusion and a third- or fourth-placed finish, which will bring Champions League qualification but not true satisfaction.

Arsenal moved up to third with this Alexis Sánchez-inspired win and it was a strange kind of non-event, given Arsenal's superiority from the outset and West Bromwich Albion's lack of body-on-the-line endeavour. This was not really a Tony Pulis performance but, then again, his club's season is set on an even more certain course.

Sánchez has found form, albeit a little late in the day, after the hamstring injury that derailed him at the end of November and held him back for longer than expected. He scored his 15th and 16th goals of the club season and Arsenal could enjoy only a fifth Premier League win in 13 matches.

The attendance was a principal sub-plot and there were degrees of apathy on show. Some regulars had indicated that they would not turn up and they proactively put their seats on a ticket exchange for fellow members. Others could not be bothered to do that, and they simply did not turn up. The stadium was dotted with empty seats.

Sánchez was in the mood at the outset and the breakthrough was marked by his sharpness of mind and body. Sandro, who was back in the West Brom team – the only change from their home loss to Watford on Saturday – was badly caught out.

In the time that it took Sánchez to collect Aaron Ramsey’s pass, spin 180 degrees and tee up a right-footed shot from the edge of the area, Sandro was barely able to complete his own half turn. Sanchez’s effort flashed low into the bottom corner and the Chilean could celebrate a goal for the fourth game in succession. Sandro was substituted at half time.

Arsène Wenger had complained beforehand that opposing teams were sitting even deeper than usual at the Emirates Stadium and West Brom appeared determined to remove whatever sting there was from the game, even when they were a goal down. The goalkeeper, Ben Foster, was barracked by the home crowd for taking his time over a goal kick as early as the 16th minute and there would be further such gripes before the midway point of the first-half.

Arsenal called the tune but West Brom did go close to an equaliser when Gareth McAuley rose unmarked to thump Darren Fletcher's 29th-minute corner against the crossbar while there had been a curious moment just beforehand. Sánchez miscontrolled a high ball inside the area and he sent it into his hand, which was raised. There was a shout for a penalty but the referee, Jon Moss, was unmoved. After Saido Berahino's two misses from the spot against Watford, perhaps it was just as well.

Moss was back in the middle after his horror show in Sunday's 2-2 draw between Leicester City and West Ham United. This game was not too big for him and he pressed on with his one-man campaign against grappling, inside or outside of the box. He booked McAuley for a tussle with Olivier Giroud close to halfway.

Mesut Özil had seen a shot blocked early on and, in the 34th minute, Foster allowed his slightly scuffed effort from Héctor Bellerín's cut-back to go through his legs. It dribbled towards goal but Craig Dawson was on the line to hack clear.

Sánchez's second came after Claudio Yacob tripped Ramsey on the edge of the area and West Brom's defensive wall failed to do its job. Per Mertesacker and Giroud stood on the end of it and, when they parted ways, Sánchez blasted through the gap. Foster was rooted.

West Brom knew that victory would lift them three places to 11th in the table but they have long since achieved their principal target, which was to remain safe. They have done so with the minimum of fuss, without ever looking as though they might be sucked into trouble and, for that, Pulis deserves plenty of credit.

The manager, typically animated inside his technical area, brought on the striker, Salomón Rondón, at half-time and he asked Berahino to play off him, but the second half brought little excitement.

Alex Iwobi and Mohamed Elneny went down inside the area, the latter a little theatrically, but Moss gave neither penalties nor yellow cards for diving – which would have been noted by Leicester's Jamie Vardy.

It was not Özil's night, and he was thwarted by Foster and then the substitute Jonas Olsson in quick succession while another substitute, Joel Campbell, and Giroud went close before the end.

(Guardian service)