The Neath valley club won two promotions in three years to work their way up from the fourth to second division and they maintained that good form with an 8-3 victory over BP Llandarcy.
Former Pontypridd prop Aled Griffiths, now player-coach at Ammanford, said: "We've really worked hard to get things right at the club, all the way down from the first team to the juniors, and its done us well over the past few years.
"Division Two is a big step up and will really test the strength of our squad, but this was a great start. Stopping them scoring a try was as pleasing as the win."
Hooker Craig Kelly scored the game's only try while BP Llandarcy are likely to find the new league far more challenging than their Division Three south-west triumph last season.
Loughor missed out on promotion last season but showed their intent for the new campaign with a seven-try rout against Gorseinon, winning 57-10.
Cardigan laid an early claim in Division Three with a comfortable 54-7 win at Llanelli Wanderers while Newcastle Emlyn also impressed, heaping more misery on Tumble who were relegated last season, with a 47-6 defeat.
Skewen claimed a bonus-point victory in Division Three south-west with a 23-21 win at Kenfig Hill. Tycroes were the only team to do the same in Division Four after a 33-3 victory against Cwmgors.
Cefneithin missed out on the Division Five title last season to Burry Port but showed they are ready to go one better with an emphatic 57-3 victory over St David's.
In the East, Llantrisant backs coach Mike Thomas is all set to give his players extra kicking practice after the first weekend playing under the new ELVs.
Having seen his side, relegated from Swalec Division One East last season, get off to a winning start in Division Two East with a 22-8 home win over Rhydyfelin, Thomas decided more work was needed top get to grips with some of the new laws.
"We got caught out a couple of times when kicking from our 22. We also got caught by the Rhydyfelin backs with their counter attacking from our kicks," said Thomas.
"Kicking is a vitally important part of the modern game and it is something we need to spend more time thinking about and practicing. It's not just about the kick, but also the chase.
"We've worked hard on our fitness throughout the summer, but we'll have to do a bit more given the extra ball in play time the new laws are bringing with them."
Thomas' fellow coach, ex-Pontypridd forward Carl Groves, had his son Jevon playing in the pack. Groves jnr was a member of the Wales Under 20 side at the IRB Junior World Championships this summer and is in the Cardiff Blues Academy.
He and fellow Under 20 cap Pat Palmer made a huge difference to the Llantristant pack and laid the foundation for a victory that wiped away some of the misery of last season's relegation.
Wing Sion Griffiths grabbed the all important Llantrisant try and scrum half Ian Worgan did the rest of the damage as the home side ended a run of five successive league defeats and won their first home league fixture since April.
Last season's Division 3 South East champions, Bedlinog, gave notice of their quality and ambition with a 13-3 home win over Abercynon on their debut in the division, while
Tredegar, who finished fourth in the division last season, had two tries from Rob Smith in their 24-7 home win over Ynysybwl.
Two tries from wing Luke Exton were at the heart of Gwernyfed's 24-21 home win over Newport HSOB. Last season's Division Four East champions also had a try from full back Gareth Dodd and nine points from the boot of Danny Skyrme.
Nantyglo finished just outside the promotion places in Division Four East last season and gave notice they intend to do better than third place this term with a battling 13-12 win at Risca. The only other game in that division saw Chepstow steal a 12-7 home win over Tredegar Ironsides thanks to tries from Chris McVay and Chris Tyrill.
Talywain picked up a bonus point in their 29-5 triumph over Ynysddu in the only game in Division Five East, while Crickhowell were 15-8 victors at Beaufort in the only surviving fixture in Division Six East.
