Lapsley try sees Derry seize the day to win again
City of Derry's revival took a significant step forward at Thomond with coach Paul O'Kane's side managing to take four vital points after winning 16-13.
It also meant that Derry put together back-to-back victories and, though they stayed in seventh, there is now some breathing space between themselves and the bottom three.
This was also the north west squad's first away win of the campaign and though the contest was closely fought throughout, the visitors grabbed the result after Alex McDonnell's break put David Lapsley over the line.
McDonnell converted to end the afternoon on 11 points after earlier kicking three penalties.
There was drama at Thomas Mellon Playing Fields when fourth-placed Omagh prevailed 27-26 over Bruff who are a place above them.
Coach Phil Marshall's men scored five tries and nailed their bonus point after Stewart McCain crossed the Bruff line which allowed them close the gap in the table with Bruff to just two points.
Elsewhere in 2C, Bangor fell to another loss this time to bottom team Seapoint by 13-0.
Third-placed Rainey Old Boys defeated Belfast Harlequins 19-10 in their 2B Ulster derby at Deramore with Andy Magrath scoring two tries and Oisin Quinn one as the visitors went 19-0 ahead in the first half.
Quins came back through Paul Kerr's penalty and conversion of Mark Glover's late try but they failed to take a losing bonus point and have also now dropped to ninth, just a point off bottom side Sundays Well.
Dungannon switched places with Quins and are now in eighth after a 25-10 home result over Wanderers with Mervyn Brown scoring twice.
In 2A, Queens's University managed their fifth try bonus of the campaign when they defeated Navan 26-7 at the Dub. The win saw the students move up a place to fifth.
Div 2A: QUB 26 Navan 7
Div 2B: Quins 10 Rainey 19, Gannon 25 Wanderers 10
Div 2C: Bangor 0 Seapoint 13, Omagh 27 Bruff 26, Thomond 13 Derry 16