Paul McGinley protected his endangered 10th place on Europe's Ryder Cup table by making the cut on level-par 142 after a 70 but his rival Paul Broadhurst missed the cut on seven-over after a 76.
The Irishman looked certain to make the team for the K Club after winning the Volvo Masters at the end of last season, but has slowly slipped down the standings.
Just three weeks remain after this before the team is finalised, but there could still be plenty of changes with next week's USPGA championship at Medinah followed by the lucrative WGC Bridgestone Invitational and the final counting event, the BMW International, in Munich.
Denmark's Soren Kjeldsen held the Dutch Open second-round clubhouse advantage on Friday although with over four hours lost to thunderstorms the halfway lead will not be decided until Saturday.
Danes dominated the leaderboard as first round joint-leader Anders Hansen finished an disrupted second round 73 in near darkness to lie one shot behind his compatriot.
Kjeldsen's three-under 68 took him to six-under 136, a stroke ahead of Hansen and Irishman Damien McGrane, who shot 68 in the morning session.
However, Spaniard Ignacio Garrido is two shots better on eight-under with seven holes still to play when the second round resumes at 0600 GMT on Saturday.
The other first round leader, Christian Cevaer of France, is on six-under with seven holes to complete and Briton Raymond Russell is five-under with eight holes left.
Kjeldsen had barely started his morning round when lightning and a torrential downpour brought the players in for two hours and 15 minutes.
He resumed brightly with a birdie on the fifth but then ran up a double-bogey on the seventh before an exhilarating back nine produced two more birdies and an eagle on the 16th.
McGrane, who has played two more events this season than Kjeldsen, had a faultless 68 as he made his latest bid for a maiden tour title.
A second thunderstorm in the afternoon caused another suspension, this time for one hour and 55 minutes.
Tournament favourite Colin Montgomerie, one of the players warming up for next week's U.S. PGA Championship, looked as though he would miss the cut when he played on after the suspension but rallied with four back nine birdies in five holes to lie two-under with just one hole to finish.
