Antonio Valencia scored one goal and set up another Sunday to give Manchester United a 2-1 win at Arsenal that keeps the pressure on Premier League leader Manchester City.

The Ecuador winger headed United into the lead in first-half injury time and, after Robin van Persie equalized in the 71st, darted into the area with nine minutes left to give Danny Welbeck the chance to smash the ball past goalkeeper Wojciech Szczesny.

The result kept the defending champions within three points of City and further threatened the Gunners' chances of qualifying for next season's Champions League.

Arsenal is five points behind fourth-place Chelsea and 18 behind City. Fans jeered manager Arsene Wenger's decision to substitute young winger Alex Oxlade-Chamberlain with the score at 1-1 and many left well before the final whistle.

Wenger left fan favorite Thierry Henry out of the squad, and the on-loan New York Red Bulls striker watched from the stands while Ryan Giggs showed the difference a veteran can make to big games.

The 38-year-old former Wales international showed a glimpse of his old pace by twisting and turning up the inside right channel to win a free kick on the edge of the area.

That chance amounted to nothing but his next significant contribution was to float in the left-wing cross that Valencia headed in at the far post.

United enjoyed plenty of possession with Michael Carrick probing patiently from deep and Giggs, in his 48th game against Arsenal, showing mobility and vision to consistently put the ball into dangerous areas.

But Rooney was too deep to be a real danger, and Nani wasted United's best first-half chance when he rolled the ball across goal with both Rooney and Welbeck unmarked and screaming for a pass.

Van Persie made United may for its missed chances with his 19th goal of the season, atoning for an uncharacteristic earlier miss with a first-time finish across goalkeeper Anders Lindegaard and in at the far post.

That roused the home fans but Valencia showed quick feet to cut into the area, exchange passes with substitute Park Ji-sung and lay the ball off to Welbeck. The striker, who had few opportunities to impress until then, thrashed the ball into the net.

But United's victory came at a cost, with Phil Jones carried off the field with what appeared to be an ankle injury, Nani limping off in the second half and Wayne Rooney hobbling at the end following a heavy challenge from Alex Song.