(CNN) -- Paul Goydos pulled ahead of overnight co-leader Justin Leonard to move into a three-stroke lead at the halfway point of the Valero Texas Open.



Goydos posted six birdies to hold a three-stroke lead after 36 holes of the Texas Open.



The American had begun the day tied on seven-under-par with former Open champion Leonard, a Texas native, who started early at the par-70, 6,896-yard Resort Course at La Cantera and followed his first-round 63 with a two-under 68 to move to nine-under.



Goydos set off in pursuit later in the day and got off to a bad start with a bogey on his first hole at the par-four 10th.



But it was to be the only blemish on his card as the 2008 Players Championship runner-up knocked off six birdies for a five-under 65 to get to 12- under-par.



"Another good day," Goydos told reporters afterwards. "Really only had one mediocre shot all day, and that was on the first hole. I made bogey, and after that I played reasonably well."



Mathias Gronberg led a Swedish charge in San Antonio, opening the day on four-under and going one better with a second-round 65 to take a share of the clubhouse lead with Leonard on nine-under.



American Ted Purdy improved by three strokes with a 67 while his compatriots John Mallinger, with a 64, and Scott Sterling, who posted a 63, made it a five-way tie overnight for second place.
How many people shared second position? Where did Paul Goydos compete? Where was the Open? Who was the first round leader? What were their scores? Who was leading after the second round of the Texas Open? Who shared the position?
a five-way tie Valero Texas Open. San Antonio, Goydos American Ted Purdy improved by three strokes with a 67 while his compatriots John Mallinger, with a 64, and Scott Sterling, who posted a 63, made it a five-way tie overnight for second place. Goydos Mathias Gronberg
question: How many people shared second position?, answer: a five-way tie | question: Where did Paul Goydos compete?, answer: Valero Texas Open. | question: Where was the Open?, answer: San Antonio, | question: Who was the first round leader?, answer: Goydos | question: What were their scores?, answer: American Ted Purdy improved by three strokes with a 67 while his compatriots John Mallinger, with a 64, and Scott Sterling, who posted a 63, made it a five-way tie overnight for second place. | question: Who was leading after the second round of the Texas Open?, answer: Goydos | question: Who shared the position?, answer: Mathias Gronberg