Hartley marched ever closer to retaining the Shepherd Neame Kent Premier League title, needing just 12 points from four games to be certain of retaining the trophy.
Closest rivals Bickley Park slipped up against Sevenoaks Vine whilst Hartley gained eighteen points at Bromley despite losing their first three wickets for just 61 after batting first at Plaistow.
But James Thompson joined Charlie Hemphrey and began to rebuild the innings. Hemphrey made a steady 81 and Thompson went on to make his second ton in two weeks, reaching 106.
He was assisted by a breezy 38 by Scott McKechnie as Hartley topped 300, ending on 312 for six, an imposing total to chase. Despite a maiden Premier century by Calum Basey, 102, and 67 by Richard Selvey-Clinton, Bromley fell behind the rate and ended 44 runs short with six down.
Perhaps the highlight of the day was an impressive third wicket stand of 225, at the expense of Sibton Park, between two Beckenham youngsters William MacVicar and Jamie McCulloch.
MacVicar was on 48 when he lost his partner Alex Blake for also 48 at 104 for three, when he was joined by eighteen year old McCulloch. Both batted superbly. McCulloch scored his maiden Premier century in just 78 balls and MacVicar piled on runs at the other end to reach an unbeaten 169 as Beckenham posted the formidable total of 347 for four.
Facing a task of almost seven an over Sibton lost early wickets and never looked likely to threaten the Beckenham total. Ben Allon made 71 and John Osborne 41 but the result was sealed and Beckenham won by 154 runs.
There was also a fine batting display at Lordswood where the home side were defeated by ten wickets by Blackheath. Despite 78 from skipper Lyndon Lockhart and 50 from Matt Greenwood, Lordswood were bowled out for 194, having elected to bat.
Dipyan Paul was the pick of the Blackheath bowlers with 3-30. In reply Jahid Ahmed blasted 100 from 65 balls and Daniel Bell-Drummond a comparatively sedate 77 from 75 as the pair knocked off the runs in just 23.1 overs.
Luke Blackaby with 88 formed the backbone of the Sevenoaks Vine innings as they set Bickley Park 243 to chase at Bickley. Dan Magin gave Bickley a glimmer of hope, but his departure for 85 with the score becoming 178 for five sealed Bickley's fate as they slipped to 218 all out earning the Vine a 25 run victory, eighteen points and a jump out of the relegation zone.
Whitstable recorded their first win of the season against Bexley, perhaps a little consolation for what would appear to be their impending relegation. In a low scoring affair at the Belmont Bexley invited their hosts to bat.
Mehdi Abba took 4-29 as Whitstable were dismissed for just 188, with both Ben Purcell and Jake Guinan scoring 38 and Max Campbell 30.
Bexley found batting heavy weather on a bowler friendly pitch. Nichoas Bills took 4-40 as Bexley slid to 123 all out, only Aiden Griggs batting at nine scoring 40 adding some respectability to a disappointing 123 all out by Bexley.