Sam Gallagher scored his first senior goal as Southampton beat Yeovil to reach the fifth round of the FA Cup.
The 18-year-old fired home from a tight angle after a fine solo run to double the hosts' advantage after Guly Do Prado's opener.
Brazilian Do Prado scored his first goal in 44 games from the penalty spot after Shane Duffy's handball.
Steven Davis almost added a late third but was denied by Yeovil keeper Marek Stech.
It was a somewhat harsh scoreline on Gary Johnson's Championship side, who were looking to reach the fifth round for the first time since 1949.
Although Jay Rodriguez and Adam Lallana saw efforts hit the woodwork either side of Do Prado's penalty, Yeovil were proving a handful and it took Gallagher's goal to put the game beyond doubt.
Gallagher joined Southampton from Plymouth's Under-16s and made his first-team debut in the Capital One Cup defeat by Sunderland in November. The 6ft 4in striker has represented Scotland at Under-19 level.
The Glovers began brightly at St Mary's, with Ishmael Miller causing a nuisance from the outset on his first appearance since he
on loan from Nottingham Forest for the rest of the season.
The 26-year-old was full of running and forced a corner off Nathaniel Clyne in the 12th minute, with Duffy's header from the resulting corner on target but lacking the power required to threaten Kelvin Davis.
Lallana, whose professional debut came in a League Cup match against Yeovil in 2006, saw a shot blocked before Rodriguez rattled the crossbar with a powerful header.
Saints continued in the ascendancy and the opening goal arrived in the 23rd minute, with referee Phil Dowd pointing to the spot after Duffy was adjudged to have handled in the box.
Rodriguez looked set to take the resulting penalty but handed the ball over to Do Prado, who sent Stech the wrong way for his first goal since 14 January 2012.
Lallana flashed a strike wide and then saw a cross-cum-shot skim the bar after Yeovil had a penalty shout of their own waved away, before Davis' reactions kept Saints ahead.
Good play down the left between Joel Grant and Joe Ralls saw the ball played in for James Hayter, whose goal-bound effort was denied by a point-blank stop by the Saints goalkeeper.
Rodriguez saw a shot deflect behind and James Ward-Prowse saw an audacious dipping effort go close, with Clyne and substitute Gallagher soon forcing Stech into saves of differing quality.
Saints went clear with 20 minutes remaining when Gallagher, on for Do Prado in the 56th minute, showed impressive poise and skill to jink clear and fire past Stech from an acute angle.
Substitute Davis saw an attempt impressively clawed away by Stech late on, with the Czech goalkeeper also denying Gallagher after the forward made himself space with impressive control.
Southampton captain Kelvin Davis said the club were hoping to move on following an altercation involving team-mates Dani Osvaldo and Jose Fonte:
"What has happened has happened. As a team, as a squad, as a club, we are looking forward and we are very much together.
"We showed that again in this game and it is something we just want to move on from. It is something we want to move on and concentrate on what happens out there [on the pitch].
"Our dressing room is as solid as it has ever been and it will continue to be so."
Yeovil boss Gary Johnson:
"They probably needed the second goal because until that point we were certainly in the game.
"We were part of a good football match. We played our game and tactics and kept them down to only a few chances and created a few ourselves, so I was very proud of our team in the first half.
"I don't know if it was the hailstones but that coincided with us losing a bit of confidence and faith in our game and Southampton took over and started working our keeper more."
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