Performance results from the first science run of ZEPLIN-III

The ZEPLIN-III experiment has just completed its first stage at the Boulby Underground Laboratory in search of dark matter WIMPs. We report on the successful operation of the instrument over the continuous 5-month run devoted to collection of WIMP search data and extensive calibration, and present preliminary performance results. Low threshold in the light and ionisation channels and excellent discrimination of γ -ray backgrounds have been achieved.