Halep won tournaments in Germany and the Netherlands just prior to Wimbledon. She won for the 14th time in 15 matches, beating Timea Babos 7-5, 7-1 in Friday's quarterfinals.
Halep won 57 percent of the points when receiving serve and finished off seven breaks, including four in the second set.
She next goes against Alexandra Cadantu, who defeated Shahar Peer 6-0, 7-5. Cadantu was 6-for-6 in break-point opportunities.
Yvonne Meusburger was a 6-4, 6-1 winner over fourth-seeded Annika Beck and No. 6-seeded Chanelle Scheepers got past Danka Kovinic 4-6, 6-0, 7-6 (7-5) to set up the other semifinal.
Scheepers and Meusburger are 2-2 in the previous matches but they haven't met on the court since 2008. Halep is 2-0 versus Cadantu.