The 19-year-old, racing in his first year in F2, made a superb start to beat pole-sitter Mirko Bortolotti off the line and lead the packed field into the first corner where he remained until the end of the race.
As Pineiro led the way off the line, Bortolotti had to fend off the attentions of race one winner Jack Clarke, who again made a rapid start from third place on the grid and tried a move up the inside of Paddock Hill Bend but was forced out by the Italian.
With the top three pulling away, Romanian Mihai Marinescu spent much of the race fending off German Tobias Hegewald with the two finishing fourth and fifth respectively.
Meanwhile, title challenger Christopher Zanella was trying hard to improve on his ninth place grid slot, working his way up the field to seventh but was then unable to pass Armaan Ebrahim ahead. Ebrahim's sixth spot was also his best result of the 2011 season and his second points finish of the weekend, with his race including a great battle involving Max Snegirev.
Miki Monras was looking on course for a secure fourth place but a spin at Westfield dropped him down the field, fighting his way back to ninth at the flag and passing Brit James Cole and Mikkel Mac along the way before battling with Jordan King. The 19-year-old Spaniard eventually finished ninth just behind Frenchman Benjamin Lariche who enjoyed one of his best weekends to date.
Alex Brundle endured another difficult race with two trips through the gravel early on at both Paddock Hill Bend and Sheene to run at the tail of the field.
At the front, however, Pineiro was largely untroubled and gradually extended a comfortable lead which eventually stabilized at over two seconds. The winning margin was 1.4 seconds, mainly due to Pineiro easing off towards the end to bring his car home.
21-year-old Bortolotti finished second to maintain his lead in the drivers' standings with Clarke claiming third spot and rounding off a fantastic weekend for the Brit on home soil.
Speaking afterwards a delighted Pineiro said: "It's just fantastic. Coming from a series of disasters that have happened all the way through to then turn it around at Brands Hatch, both yesterday and the win today, is just great and a boost for the next rounds."
The next rounds of the 2011 FIA Formula Two Championship take place at the Red Bull Ring in Austria on 26-28 August.
Brands Hatch, race two, Top-10 results:
1. Ramon Pineiro, 28 Laps
2. Mirko Bortolotti, +1.484s
3. Jack Clarke, +3.511s
4. Mihai Marinescu, +21.605s
5. Tobias Hegewald, +25.736
6. Aramaan Ebrahim, +31.305s
7. Christopher Zanella, +31.745s
8. Benjamin Lariche, +38.710s
9. Miki Monras, +39.362s
10. Jordan King, +39.920s