Georgia Hall defied jetlag to stay within three shots off the lead at the halfway stage of the Omega Dubai Ladies Classic as Anne van Dam fired a superb 65 to hit the front.
Van Dam's flawless seven-birdie second round lifted the Dutchwoman to 10 under par, two clear of Scotland's Kelsey MacDonald with Hall a further stroke adrift following a confident 67 at the Emirates Golf Club.
Charley Hull lost ground on the leaders after a second straight 70 left her six behind on four under, but there was disappointment for Solheim Cup veteran Catriona Matthew after a pair of 73s saw her miss the cut by a single shot.
Van Dam was just two under for her round with eight holes remaining, but she suddenly surged up the leaderboard with three straight birdies before further gains at two of her last three holes capped the best round of the Ladies European Tour's season-ending tournament.
MacDonald made a poor start to her round when she bogeyed the 11th - her second - before reviving her challenge for a maiden LET victory with four consecutive birdies from the 15th before mixing two birdies with one bogey over the front nine.
The Scot parred her final hole to match her opening 68, while Hall went one better after following a back-nine 35 with three birdies over her last five holes which lifted her into a share of third with Celina Yuan and Thidapa Suwannapura.
Hall admitted she was suffering with jetlag and fatigue having travelled to Dubai immediately after securing her LPGA Tour card for next season at the Final Stage of Qualifying School, finishing the gruelling five-round event in a tie for seventh at Daytona Beach in Florida.
"I did putt well today and I wanted to take advantage of the morning round, because the greens were in better condition and less wind, so I'm glad I did it," said Hall. "I woke up at midnight and didn't get back to sleep, so I wasn't in the best of moods today. I'm quite tired, but I played well,"
MacDonald's compatriot Michele Thomson also carded an impressive 68 to move to six under, one ahead of English pair Florentyna Parker and Hannah Burke.
Hull also joined the logjam on five under when she birdied the second and third, but her second bogey of the day at the ninth left her six behind Van Dam heading into the final 36 holes.