The script had been written for Yaya Sanogo. Talked up on the eve of his Arsenal debut by Arsène Wenger as a player of high class rather than a high price tag, the club's only signing of the summer so far found himself in on goal with his first touches for the club. Only 42 seconds had elapsed. This stood to be quite a way to announce himself and, perhaps, to buy a little breathing space for Wenger.

The 20-year-old's burst and ability to skate away from his defender, after Alex Oxlade-Chamberlain had won possession to spring him forward, were encouraging. Yet the right-foot drive was snatched and it produced a regulation save out of the Galatasaray goalkeeper Fernando Muslera. Sanogo's instincts in front of goal until his substitution on 61 minutes betrayed him. Perhaps it was the nerves; the scrutiny upon him was great.

He was touched through by Santi Cazorla on 41 minutes only to rush his low shot and allow Muslera to block – he was extremely grateful to see the offside flag – and there was a wild slash over the crossbar.

Yet he and Wenger could reflect with a measure of satisfaction upon his efforts, particularly as he was only just back from a holiday after his participation at the Under-20 World Cup with France. The free agent from Auxerre has limited experience, never before having played on such a stage, in front of 59,608 fans – to him, this was no friendly. There was a positivity about his movement and link-up work and his physique marked him out as a player that will not be pushed around.

He was eclipsed, however, by an old Arsenal nemesis, a player who most surely does not get pushed around. Didier Drogba has departed from Chelsea, where he hurt Arsenal on countless occasions, but he returned to haunt them here in Galatasaray colours.

On as a half-time substitute to pantomime boos, he won and converted a penalty after the Arsenal substitute Ignasi Miquel had lost his bearings and touched into the back of him. "It was very, very, very, very, very, very soft," Wenger said, torn between amusement and frustration. "It was a classic Drogba." His reaction after a competitive match would have majored on the latter.

This was a cameo of bullying authority from the Ivorian and yet there was glorious finesse to him as he crafted the game's decisive moment. From the substitute Wesley Sneijder's floated pass, he peeled away from Per Mertesacker to bring the ball down and back inside in one touch before thumping a left-foot finish past Wojciech Szczesny.

He had celebrated his first goal by referring the Arsenal support to the name across his shoulders and he slid upon his knees after bringing Arsenal to theirs with only three minutes to go. Galatasaray are this summer's Emirates Cup winners and the sting for the home support was the sight of Emmanuel Eboué, the one-time Arsenal cult hero, hoisting aloft the trophy at this stadium. Eboué had been named as the Galatasaray captain to commemorate his return.

Wenger's continued attempts to make a statement signing had provided the backdrop to the occasion. It is ever thus. 'You can't buy class,' read one supportive banner in the crowd but that, of course, is not true. The market does contain it. Arsenal's top target Luis Suárez, for example, is class.

Maybe it was a taunt? Wenger, you can't buy class. He continues to try his best during the current window, although the updates here concerned outgoing business. Gervinho is close to an €8m (£7m) transfer to Roma; Marouane Chamakh to a move to Crystal Palace, possibly on loan.

Wenger, who has an interest in the 18-year-old Freiburg centre-half Matthias Ginter, was pressed on a timeframe regarding signings and he did not sound positive. "It's very difficult to predict if something will be sorted out before we play in the Champions League qualifier," he said. The first leg of the tie is scheduled for 20 or 21 August.

The atmosphere was spiced by thousands of Turkish fans, a little niggle between the players in the first half and Mexican waves after the interval.

Arsenal fans sought the usual clues as to Wenger's thinking. He once again used Oxlade-Chamberlain in a central role while Bacary Sagna, again, played at centre-half. With Thomas Vermaelen injured and Johan Djourou loaned out, Arsenal look thin in the position. Aaron Ramsey, meanwhile, kept up his eye-catching pre-season form.

Arsenal went in front through Theo Walcott. The forward had missed a clear chance in the 18th minute but he profited when he bent an in-swinging cross from the left, which kept on going to find the far corner. Wenger's team were slick in the first half yet they could not maintain their pace or rhythm. Drogba meted out the punishment.