The 20-year-old was only called into the starting XV as a late replacement for captain Gareth Maule who pulled up ten minutes before kickoff, but he more than made up for his absence with a man-of-the-match display capped by a try at the start of each half.
Flanker Richie Pugh and prop Rhys Thomas also crossed for Nigel Davies' side while Edinburgh were left empty handed despite tries for wingers Tim Visser and Lee Jones.
The Welsh side had lost all four of their previous league games but set about their Scottish opponents early on, taking a quick 13-point advantage which was never reined in after Warren's try on 15 minutes.
Aled Thomas, on loan from London Welsh, had dispatched a long-range penalty on 11 minutes for the hosts before Warren, making his first ever league start, then scored his opportunist effort.
The Welshman blocked Gregor Hunter's attempted clearance and scooped the ball ten metres out before going under the posts. Thomas, taking up kicking duties for the first time this season, added the extras before adding three more on 22 minutes.
Not to be outdone, Greig Laidlaw, who had 65 points for the season prior to the match, gave Edinburgh a toehold in the match with a penalty before Dutchman Tim Visser went over in the corner after Grant Gilchrist's off-load on the half hour.
Laidlaw added the extras to bring the Scots within three points.
The second half started in much the same vein as the Scarlets took full advantage of lethargic Edinburgh defence. Warren going over for his and Scarlets' second try on 48 minutes.
Just past the hour mark, Scarlets moved ten points clear after Pugh powered his way over the line as the Edinburgh defence, still recovering from John Houston's sin-binning on 52 minutes, tried desperately to halt wave after wave of attacks.
A minute later though, Jones' expert solo effort brought Edinburgh back into the contest, beating three defenders from inside his own half for a well taken try.
Jones penalty on 69 minutes gave Nigel Davies' side breathing space before Rhys Thomas' late effort snatched his side's first five-pointer of the season.
|Scarlets Score Card|
|Rhys M. Thomas||1||5|
|Edinburgh Rugby Score Card|