Tesco can go ahead with plans for a new superstore despite claims it will damage the character of Carmarthen.
The planning committee visited the site on Tuesday
In a close vote on Tuesday the supermarket chain was given permission to develop Five Fields which includes Carmarthen Athletic rugby ground.
Tesco said its present store in the town was too small to meet customers' needs and parking provision was poor.
But opponents said an 87,000 sq ft shop on the outskirts of Carmarthen would hit town centre trade.
The Campaign for the Protection of Rural Wales (CPRW), along with Carmarthen's town council, civic society and chamber of commerce opposed the application.
Carmarthenshire Council's planning committee visited the site on Tuesday where it was met by a small group of protesters.
When members discussed the application they heard from traders who claimed it could turn Carmarthen into a ghost town.
Ivor Russell, branch secretary of the CPRW said in a statement: "This application is too large relative to the size and population of Carmarthen.
"Its size appears to be intended to be a magnet to draw shoppers from other areas of south west Wales.
"As such the very admitted success of Tesco must drain life and activity away from Carmarthen and other town centres."
But members of the planning voted eight to six in favour with one abstention.
Carmarthen Athletic RFC had not opposed Tesco's plans as it will have the finances to move to a new modern ground.
The Five Fields site is currently home to Carmarthen Athletic
Tesco had revised its plans to try to address some of the concerns and had cut back the size of the non-food sales area it was planning.
It also paid for a retail impact study which concluded it would take little trade from other businesses.
The existing Tesco site will be used for additional car parking in Carmarthen.
A spokesman said after the meeting: "Tesco is delighted that the committee resolved to approve the application for a replacement at Five Fields for a new modern store.
"It will further add to the appeal of Carmarthen as a regional shopping destination."
Objectors, including town mayor Philip Grice, said they would now try to persuade the Welsh Assembly Government to call the application in.
"I think there is still quite a long way to go before this goes ahead," he added.
"I hope that the developers that were here today listened to what was said because this development is still far too big for Carmarthen.
"It's in the wrong position, it's going to create traffic chaos and it's going in my view, and the view of the town council, to ruin many businesses that already exist in the town."