Arsenal kept alive their hopes of a top-four Premier League finish as second-half goals from Alexis Sanchez and Olivier Giroud earned victory at Southampton.

After a dull first half, Sanchez produced a moment of magic to open the scoring when the Chilean wrong-footed two defenders in the box before calmly slotting home.

Substitute Giroud then made the win safe by nodding in from close range minutes after coming onto the pitch.

Mid-table Southampton rarely threatened. Their best chance came in the first half when Manolo Gabbiadini forced a fine save out of Petr Cech from close range, and they stay 10th.

The win means Arsenal move above Manchester United into fifth, three points behind fourth-placed Manchester City.