David Moyes may be getting his message through to Manchester United but Ashley Young remains impervious to warnings about diving. The England international performed another trademark tumble to win a penalty at Real Sociedad but justice was served as Robin van Persie struck his spot-kick against a post. United should have secured a rare victory in Spain without recourse to controversy.

"A missed opportunity" was Moyes's description of the goalless draw in the Basque country and his team had plenty of chances to extend their lead at the summit of Group A. Javier Hernández missed an open goal from six yards and Van Persie hit the same post from open play plus the penalty spot before Marouane Fellaini was sent off in the 90th minute for a second bookable offence. Fellaini had flirted with trouble for an hour as he again struggled to impose himself in the centre of United's midfield, but it was Young's performance that left the sourest taste.

The United winger's theatrics have become so routine that even Sir Alex Ferguson condemned his own player two season's ago. Ferguson added that the problem had been eradicated from Young's game – but evidently not. Young, cautioned against theatrics by Moyes earlier in the season after a controversial display against Crystal Palace, had been on the pitch six minutes when he felt a slight pull from Markel Bergara and executed his dying swan act. Estadio Anoeta was stunned into silence as the Italian referee Nicola Rizzoli pointed to the spot and booked the Sociedad midfielder. The place erupted with justifiable glee when Van Persie's venomous penalty rebounded to safety off the woodwork.

Controversy was unnecessary. United, with Shinji Kagawa impressing both on the left wing and when moved into a central role, were in control without catching the eye. The few openings they did create were clear enough to improve their meagre record of only two wins from 22 trips to Spain, though it is now eight matches unbeaten for Moyes's side and they remain in a comfortable position in their group.

Hernández, his future under scrutiny in the absence of a regular starting role, made an immediate impression on Sociedad's Iñigo Martínez and was somewhat fortunate an elbow into the central defender's face was deemed accidental. The Mexico international clearly checked where Martínez was before raising an arm into the player whose own-goal decided last month's match at Old Trafford and left the Basque club pointless in Group A. Sociedad's players, in fairness, did not stage much of a protest.

Of the three United starters under pressure to stake their claim for more regular football it was Kagawa who stood out as the visitors made a composed start. The left wing may not be the ideal platform for the Japan international to showcase his strengths but he was prominent in all of United's chances in the first half and the only visiting player who threatened to unlock the home defence.

Kagawa linked well with Patrice Evra down the left and a slick combination between the pair, plus a flick from Rooney, presented the midfielder with the first opportunity of the night. His low shot deflected wide of Claudio Bravo's goal but the Sociedad keeper was forced to act when Kagawa released a powerful drive from the corner of the area after more good work from Rooney. Kagawa turned provider when he beat Carlos Martínez to the byline and sent an inviting cross towards Hernández at the near post only for Iñigo Martínez to intercept well. For all United's control in the first half, that was the sum total of the threat they brought.

Considering Jagoba Arrasate's team had to win to guarantee their interest in the tournament remained alive, Sociedad were strangely subdued in the opening exchanges. The home side were second best in the challenge and careless on the ball, but finally found their rhythm as the game progressed to stretch the United defence. Sociedad continued to press for their first win in the group stage but United should have made the breakthrough with their first attack of the second half. Almost inevitably Kagawa was at the heart of the chance, toying with Carlos Martínez at right-back before threading the ball through three defenders across goal. Hernández arrived unmarked behind the last man but, with the goal gaping, somehow skied his left-foot shot high over the bar from six yards. The striker immediately turned to look for an offside flag, as though it could lessen his embarrassment, but it stayed down.

Hernández and Rooney were withdrawn shortly afterwards and the switch immediately injected greater urgency into United's play. The introduction of Van Persie and Young allowed Kagawa to move into his favoured central role behind the Dutchman and the midfielder, rightly denied a penalty following a fair challenge by Mikel González that brought appeals from Moyes, continued to shine. His first act there was to release Young down the left. Young swept the ball across the Sociedad goalmouth and Van Persie, like Hernández before him, arrived unmarked only to hit the outside of the post from a difficult angle. That miss was unfortunate. His next encounter with the post was an embarrassment for Young.