The Wanderers hit the front with a 50 metre interception try from Haydn Palmer and Sean Coughlin's conversion and penalty gave them a 10 point lead. By half-time Dave Gratton had cut the gap by three points and then a try by the same player made it 10-8 at the start of the second half.
Coughlin converted Palmer's second try for the home side and then added a penalty, but further Ystrad tries from Sam Jones and Tom Hetherington, one of which Gratton converted to level the scores.
A last gasp penalty from inside his own half by Ian Davies earned Gilfach Goch a 30-28 victory over Treorchy, while a hat-trick of tries from outside half James Powell helped Penallta earn a bonus point in their 33-18 triumph at Nelson. There was also an impressive win on the road for Ynysybwl, who beat local rivals Rhydyfelin 28-24.
Right wing Lee Bendon raced over for two of Rumney's three tries in their 23-16 home win over Bedlinog, while there were also two tries for Ioan Williams in Merthyr's 24-20 home triumph over Heol y Cyw.
In Division Two East the newly promoted Dowlais showed their potential with a five try romp at home as they beat Abercynon 29-5. The other new boys, Abertillery BG also got off to a winning start as they triumphed 13-10 at Senghenydd..
Llanishen stormed to the top of the table thanks to their eight tries in a 45-15 win at Garndiffaith, while seven try Mountain Ash also went on the rampage on the road as they won 47-21 at Tredegar. There was also a bonus point win for Llantwit Fardre in their 38-11 home victory over Fleur de Lys.