Seven-time major champion Venus Williams has lost her first competitive singles match since injuring her hamstring in January, succumbing to 17-year-old Celine Naef 3-6 7-6 (7-3) 6-2 at the s'-Hertogenbosch grasscourt tournament. With family members including her sister, Serena, in the stands, the 42-year-old Williams battled temperatures around 30 degrees Celsius and an opponent making her WTA debut to win the first set before losing a second-set tiebreaker and wilting in the decider. "Amazing. I cannot believe I had the chance to play against Venus," the Swiss teenager said on court after Tuesday's victory. "She's an amazing player and really a role model for everyone." Williams injured her hamstring in January in Auckland. She broke first in the second set but Naef fought back to force the tiebreaker and dominated the deciding set. Kimberley Birrell beat Lesely Pattinama Kerkhove 6-1 6-4 to progress to the second round in the Netherlands but fellow Australia Priscilla Hon is out after losing 6-3 6-0 to American Sachia Vickery. In the Nottingham tournament defending champion and recent French Open semi-finalist Beatriz Haddad Maia suffered a surprise defeat to Ukrainian lucky loser Daria Singer, going down 6-4 6-3. Australia's Olivia Gadecki lost 6-4 6-4 to Polish world No.21 Magda Linette. - with PA Australian Associated Press