Gonzalez posted a second consecutive 7-under-par 65 and improved to 14-under 130 after 36 holes. Bernd Wiesberger, who shared the first-round lead with Gonzalez is second at 13-under. He shot 66 Friday despite back-to-back birdies midway through his round.
Tommy Fleetwood matched the 65 by Gonzalez and is tied for third with Mark Foster, who shot 67 in the second round, at 11-under 133.
Brooks Koepka, with a 66 Friday, is alone in fifth at 10-under.
Gonzalez was 3-under through 12 holes before giving a stroke back at the par-4 13th. He then ran off five straight birdies, playing the second nine of the Gleneagles Hotel course in 32 for the second time.
Wiesberger, like Gonzalez, had birdies at Nos. 2 and 3 and he also birdied the fifth hole but he dropped back with bogeys at 7 and 8. He posted birdies at 10 and 11 to get those strokes back.
He got to 4-under for the day with a birdie at 14 and closed the round with two consecutive birdies.
The formal name of the tournament is the Johnnie Walker Championship at Gleneagles.