Fifth seed Carlos Moya secured his third Copa Telmex title with a 7-6 (8/6) 6-4 win over Italian Filippo Volandri.
Playing his third final in the last four years at the £258,300 clay court event, the Spaniard always looked in control after winning a crucial first-set tie-breaker against his sixth-seed opponent, who had blown a pair of set points.
Moya said: "I am very happy. The beginning of the match was very difficult because he started off playing really well. Once I broke back I started seeing that he was a bit tired and that helped me a lot.
"I am very happy to be winning the title here, it hasn't been easy this week.
"This tournament means a lot to me, I won my first title here and I feel at home in Argentina."
That first career title came in 1995, but he had to wait until 2003 before winning this tournament again, reaching the final in the defence of his title two years ago.
The 1998 French Open champion, Moya improved to 19-20 in ATP Tour finals and won his first event since Chennai, India last year, where he also reached the final last month before losing to Croatian Ivan Ljubicic.
Volandri slipped to 1-5 in career finals and 1-5 record against Moya.
He won his sole title in the clay court event in St Polten, Austria two years ago.
Despite the defeat, he was pleased with his performance after losing in the first round last year.
"Even though I lost, I played a good match," Volandri said.
"I had good chances in the first set - I had two set points.
On one of the two, I played a bad forehand. In the second set, I didn't have so many chances because he started to serve very well. But it was still a great week."