Gulbis ended up with a 3-6, 6-4, 6-0 come-from-behind victory by controlling the second half of the match.
Garcia-Lopez had an early second-set break for the large lead but Gulbis won the last four games of the second set to even the match. He followed that with quick breaks in the first two games Garcia-Lopez served in the third set and cruised in from there.
Gulbis finished with six breaks, with five in the last two sets. He dropped just five points in putting the match away in the third set.
The win allowed Gulbis to stay perfect in ATP finals appearances. He's 4-0, including a win at Delray Beach, Fla., earlier this year. Garcia-Lopez is 2-3 in finals, within another of the second-place finish last April. His most recent tournament win was in October 2010.
Gulbis collected $78,000 as the St. Petersburg champion and his won more than $3.2 million in his career. Garcia-Lopez picked up the second-place check of $41,1000, giving him nearly $4.1 million in winnings since turning professional in 2002.