Eric Kinder's trailed at the break but an own goal and a John O'Sullivan penalty saw Rovers earn a share of the spoils in a 2-2 draw at Staplewood Training Ground.
It was the home side who were the busier of the two in the opening half, Rovers goalkeeper David Raya having to be alert on a number of occasions.
But there was little the Spanish stopper could do about the opening goal five minutes before the break, Tadanari Lee reacting the quickest after Ryan Seager's shot came back off the post.
Seven minutes into the second half and Rovers were level. A quick-fire break from the blue and whites saw Hugo Fernandez shoot goalwards and it was turned into his own net by defender Matt Targett.
However parity only lasted three minutes as the home side hit straight back once more through Japanese forward Tadanari Lee as Saints capitalising on a defensive error.
On 65 minutes Rovers were level again, this time from the penalty spot after trialist Brendon Daniels was felled in the area. Captain John O'Sullivan took the honours and made no mistake from the spot for his first goal of the campaign.
Southampton went about getting in front for a third time and they were the width of a post away from doing so on 72 minutes as Tadanari Lee saw his shot deflect onto the woodwork.
Rovers could have then snatched all three points themselves in the dying stages as Devarn Green broke free, but his shot was wel saved.
ROVERS: Raya, Fernandez, Bauress, R. Hanley, Daly, Tumwa, Green, O'Sullivan (sub Paulo Jorge 85 mins), Rittenberg, Zapata-Caicedo (sub Haley 62 mins), Daniels (sub Pero 85 mins).
Subs not used: Killip, Edinho.