Having gone in goalless at the break, Brad Breslan broke the deadlock 10 minutes into the second half and was joined on the scoresheet by Sean Ayre (2), Jack Baxter and Isaac Reed.
The visitors to Homers Heath Had the upper hand in the first half but were repelled by an excellent rearguard display from the home side – who also had their moments.
In fact, Buckland fashioned arguably the best chance by either side on 23 minutes when a corner was met by the head of Joe Crook. His glancing effort was just kept out by a combination of the post and Teigns skipper Myles James.
After some strong words from manager Liam Jones at the turn, Teignmouth came out with the bit between their teeth and took the lead through Breslan’s far post finish.
Four minutes later it was two when Baxter whipped a lovely free-kick on the edge of the box into the top corner.
By 65 minutes Ayre would have a well-earned brace – the first a side-foot into an empty net from the edge of the area, the second a Jake Smith strike which he deflected past Kit Glanvill.
The Bucks had long-range pot shots from Crook and Lewis Round kept out by Harrison Montandon before Reed put the cherry on top in stoppage time.
The win makes it two wins and 10 goals in less than a week for the title-chasing Teigns, who were also 5-0 winners at Bere Alston United on Saturday.
‘We were frustrated with the first half,’ Jones admitted. ‘Some harsh words were said at half-time as we were just getting a bit impatient with each other.
‘We couldn’t quite grind that chance out which was really going to put us ahead. It was disappointing as our attitude wasn’t there collectively.
‘The lads really took that on board and in the second half we ripped through the side. Our firepower was enough to see us take control of the game.
‘Some of it is down to pressure. A lot of lads have not been in this situation when you’re three or four games from the end of the season, in a cup semi-final and have a chance of winning the league.
‘It’s difficult and people will deal with it differently. Our lads are clearly doing that and we have to ensure that we guide them and don’t get the wrong emotion, which we got in the first half.’
Jones also singled out midfielder Ayre for praise, adding: ‘He’s been outstanding for us. Nobody deserves goals more based on work-rate.
‘It doesn’t matter who we’re playing or where we’re playing, he’ll work his nuts off to ensure he gives me 100 per cent. I know lads will measure it on stats, but he means more to the side than goals.’
Buckland Reserves manager Craig Hutcheson was away, leaving assistant manager Martin Brown to take the reins.
‘We asked the lads to work hard, stick together as a unit, be compact and try to frustrate Teignmouth for a long period,’ said Brown. ‘In the first half that’s exactly what they did.
‘We hit the post off a corner – Crooky is good at ghosting into those positions – and going into the second half we just asked for more of that.
‘Unfortunately I think once one goes in the inevitable happens as you can’t defend for 90 minutes like that.
‘Teignmouth are a physically strong side, they’re fit and they play to their strengths well. They get forward in numbers, they hunt in packs and they had that little bit of quality in front of goal in the end.
‘They’re not top of the league for no reason. They are quality and they obviously deserved to run out winners in the second half, but it’s a shame because our first half performance was good.’
This weekend the Teigns travel to PAFC Development, while Buckland entertain Plymstock United (both 3pm).