Gosport 147 trio Pete Oughton, Scott Stoneage and Paul Foster led the rampant top-flight leaders to a 7-5 win over Craneswater A at Southsea.
Steve Toms and Pedro Ferguson were the top home performers.
Ferguson knocked in a 52 for the A team but they are now facing the prospect of finishing in third spot.
Copnor B took advantage of Craneswater’s defeat to strengthen their grip on second spot.
They recorded an 8-4 success. Pascal Richard, Steve Baldwin and Gary Bricknell bagged a brace apiece.
But Alan Wakefield had a tough contest against Mark Tillison.
The impressive Tillison rolled in breaks of 48, 38 and 30 to leave Wakefield in his seat for most of the contest.
Portchester X seem doomed again but they held on for a 6-6 as fellow strugglers Copnor A visited.
Scott Compton and Jon Sunderland chalked up away doubles, before Andy Macey and Darren O’Hara gave skipper Jason Tame something to smile about.
Emsworth climbed back to the division two summit with a 10-2 win against Waverley.
Greg Harding was the top man with a 49 but Hugh Pollard, Phil Andrews and skipper Chris Hardiman also played major roles.
Lee Paice and Dave Egan got some luck late on but the bowlers face dropping back to the third tier.
Havant Club 1888 are also in the battle to stay up and they lost 8-4 to Leigh Park WMC A.
Early doubles by Mark Raynor, Danny Lumsden and Dusty Tingley gave the workies a cracking start.
Tony May clawed some pride back for Havant at the expense of Richie Burnett.
Cowplain Gas found it tough at Copnor D as Tony Simmons and Dave Glover gave the city outfit an 8-4 win.
Gary More registered the break of the week with a 65 but his Craneswater R team-mates could not follow his lead.
They went down 8-4 to club-rivals Craneswater Z.
Emma Bonney notched a 48 break and Simon Petrie, while Aaron Brett – with a 31 break – added doubles for the victors.
John Peers did well to draw with Jason Taylor after the latter made a 32.
Copnor E have high hopes of promotion following a hard-fought 7-5 win at Carlton.
John Shervell beat the Hillsiders captain Alan Munday 2-0.
Roger Mo equalised in the same style with a break of 31 and a black ball success.
Norman Bradfield put the visitors back in front but Mel Davis levelled the scores.
Dennis Hushley then saw off Jeff Oakes to finish the contest in style.
Leigh Park B notched their fourth win of the season with an 8-4 triumph at Alexandra Bowls.
Matt Sheath got his usual double for the home side.
But Colin Ricketts, Dave Riddell and Bill Parsons won for Leigh Park.
SESA Broadoak beat North End 7-5. Steve Scott and Barry Branscombe delivered for the victors. Ade Pledge replied.