Latvian qualifier Ernests Gulbis outlasted German second seed Tommy Haas 6-3, 4-6, 7-6 (7/2) on Saturday to reach the final of the $455,775 ATP Delray Beach International Championship.
In a matchup of past Delray Beach champions, Haas squandered three break points in the 11th game of the third set. Gulbis won the last five points to hold for a 6-5 lead, then won six of the last seven points in the tie-breaker.
US top seed John Isner and France's Edouard Roger-Vasselin meet in the other semi-final to decide who will face 109th-ranked Gulbis in Sunday's title match.
Gulbis seeks his third ATP title at the same event where he won his first tour crown in 2010. His only other tour title came at Los Angeles in 2011, also on hardcourts.
Former World No. 2 Haas, ranked 90 spots ahead of Gulbis, was denied a chance at a 14th career title at the same event where he won the 2006 crown. Haas last won a hardcourt title in 2007 at Memphis.
Gulbis, 10 years younger than Haas at 24, split two prior matches with the German, winning a five-setter in the first round of last year's US Open after a 2009 loss on Spanish clay.
Gulbis lost his only prior match against 15th-ranked Isner in the first round at Wimbledon in 2008 and has never faced Roger-Vasselin, who seeks his first career ATP singles final.
Isner, who also has never played Roger-Vasselin, seeks his sixth career ATP title, having won at Winston-Salem and Newport each of the past two years and in Auckland in 2010.