The 19th-ranked Haas, who will turn 35-years-old in March, is the oldest player ranked in the Top 50.
Haas, who reached his 25th career final two weeks ago at San Jose, Calif., before losing to Canadian Milos Raonic, will next face 2010 Delray Beach champion Ernests Gulbis of Latvia.
Haas has won 13 career singles titles — his last at Halle, Germany, last year where he beat Roger Federer in the final — and reached a career high No. 2 ranking in 2002.
Gulbis advanced to Saturday's semifinals by beating fellow qualifier Daniel Munoz-De la Nava of Spain 6-1, 6-4.