Naas' Conor O'Rourke might be the leading Irishman at the Brabazon Trophy, but he's seven shots behind South Africa's Kyle McClatchie at halfway at Woodhall Spa.
Six of Ireland's 10-strong representation missed the cut at the Lincolnshire venue with Walker Cup hopefuls Robin Dawson and Colm Campbell, international Conor Purcell and panel member Kevin LeBlanc missing out.
Tramore's Dawson opened with a five-under 68 that included a hole-in-one but after a stop-start- exam period recently, he was out of sorts on Friday and posted an uncharacteristic 83 to miss the four-over par cut by one stroke.
Campbell (73-79), Conor Purcell (79-74) and Kevin Le Blanc (71-84) also missed out, leaving O'Rourke leading the Irish charge in 17th place on three-under 143.
Lester, a recent winner of the NAIA Championship in Chicago, carded a superb, bogey-free, six-under 67 in round two to move up 68 places to tied 19th on two-under alongside Whitehead's John Ross Galbraith (71-73).
Alex Gleeson (147), Colin Fairweather (148) and Tiarnan McLarnon (150) also made the cut but like O'Rourke, they have work to do to catch McClatchie.
The South African shone for two rounds in the Irish Amateur Open at Royal County Down and he's one clear on ten-under-par at halfway after rounds of 70 and 66.
Walker Cup prospects Craig Ross of Scotland (70-67) and Lytham Trophy winner Jack Singh Brar (67-70) are second on nine-under-par with Scotland's Robert MacIntyre fourth alone on eight-under.
Brabazon Trophy, Woodhall Spa (Par 73)
*T17 O’ROURKE, Conor Naas Golf Club 71 72 143
T19 LESTER, Rowan Hermitage 77 67 144
T19 GALBRAITH, John Ross Whitehead 71 73 144
*T26 GLEESON, Alex Castle 76 71 147
T37 Ireland (a) FAIRWEATHER, Colin Knock 73 75 148
T56 Ireland (a) MCLARNON, Tiarnan Massereene 73 77 150
*MC Ireland (a) DAWSON, Robin Tramore 68 83 151
*MC Ireland (a) CAMPBELL, Colm Warrenpoint 73 79 152
MC Ireland (a) PURCELL, Conor Portmarnock 79 74 153
*MC Ireland (a) LEBLANC, Kevin The Island 71 84 155
* Indicates official GUI party