Southampton have taken a decisive step in progressing to the playoff rounds of the Europa League after vanquishing Vitesse 3-0 in their third qualifying round first-leg clash at St Mary's.

The game exploded into action as Valeri Kazaishvili's low strike across goal in the third minute, following a poor Maya Yoshida clearance, flew inches wide.

Moments later the hosts thought that they had a shout for a penalty after Dusan Tadic was brought down in the box, but the move had already been flagged for offside.

The Saints came close to open the scoring just before the half-hour mark when Victor Wanyama had a pot-shot at goal, but opposition goalkeeper Eloy Room palmed the danger away.

Vitesse hung on valiantly but were undone in the 36th minute when Sadio Mane sent an incisive diagonal ball over to Graziano Pelle, who struck a powerful effort past Room and into the net.

There was more drama to come before the half was over as Mane was brought down inside the area, prompting the referee to point to the spot.

Tadic stepped up and duly stroked his penalty home - as Room dived the wrong way - to double his side's lead on the stroke of half time.

Pelle then had the chance to nab his second goal of the day in the 55th minute, but he volleyed the ball a couple of yards over the crossbar.

Vitesse had several chances to get back into the game midway through the second half, but Southampton made sure of the victory when substitute Shane Long seized Lewis Baker's misplaced pass in midfield.

The Saints striker powered down the pitch and combined well with Juanmi, who lofted the ball into the Irishman's path for a simple header into the back of the net.