Delray Beach, FL (SportsNetwork.com) - No. 7 seed Marin Cilic of Croatia upended second-seeded American John Isner, 7-6 (7-5), 6-3 to gain a spot in the title match at the Delray Beach Open tennis event.

Cilic, who fired 12 aces, won in just under 1 1/2 hours in a match that lasted until nearly 1 a.m. ET following a rain delay of nearly three hours at the start.

Next up for Cilic will be fourth-seeded South African Kevin Anderson, who booked a passage into Sunday's final thanks to a 6-2, 6-4 victory over American challenger Steve Johnson in only 66 minutes. The 2012 champion here collected 13 aces and won 30 of his 35 first-serve points.

Johnson, a former two-time NCAA singles champion was an upset quarterfinal winner. The 24-year-old qualifier ousted sixth-seeded veteran Spanish left-hander Feliciano Lopez 6-3, 6-2 in 1 hour, 13 minutes on Friday.

Cilic, who has 10 career championships, including one in Zagreb earlier this month, has beaten Anderson in three of four all-time meetings. The 27-year-old Anderson is trying for his third career title.

The 2014 Delray Beach champ will earn $81,500.