Quiros fired a 4-under-par 67 in the second round while first-round leader Donald was 1-over and Manassero 1-under for the day. They are tied at 6-under 136 after 36 holes.
Thomas Aiken (67 Friday), David Horsey (68) and Jose Manuel Lara (70) are tied for fourth, two strokes behind the leaders.
Quiros finished his first round with back-to-back birdies and got within sight of Donald with consecutive birdies on 3 and 4 Friday. He stumbled with bogeys at Nos. 12 and 15 -- two of the four holes he bogeyed in the first round -- but had a birdie at 13 and closed with birdies at 16-18.
Manassero's round included four birdies and three bogeys. Like Quiros, he had a bogey at the par-4, 489-yard 15th hole for the second consecutive round.
Donald opened his play Friday with a bogey and, despite a birdie at No. 4, was 2-over after 10 due to bogeys at 7 and 10. He pulled back into a share of the lead with a 17th-hole bogey.