Spaniard Quiros shot a best of the day 67 that included two eagles, with France’s Dubuisson joining him courtesy of a second consecutive 69 and overnight joint-leader Pepperell firing a 72.
That was the same mark Jens Dantorp and Pepperell had set overnight at PGA Sweden National, as a stiff breeze made for a tough day, with World Number Two Henrik Stenson handily placed just a shot off the lead.
Quiros won six times on The European Tour between 2007 and 2011, but injuries and a loss of form saw him fail to record a top-three finish in either of the next two seasons.
That run ended when he was third in China last month, his second top five in three events, and now the 31 year old is in the hunt for a first win in three years.
Big-hitting Quiros had eagled the 11th and birdied the 15th and 18th to turn in 32, then hit his second shot to within five feet of the par five first for another eagle that took him to seven under.
His sole bogey of the day came at the fourth, but the former DP World Championship winner was still pleased with his day’s work.
“I’ve been hitting the ball very well from tee to green, but even with the scores I’ve had I have not putted great,” revealed Quiros.
“I had one putt from eight metres for eagle on 11, but apart from that I’ve had a lot of putts from around five or six metres and not holed any. So even though I’m happy I could have putted better.
“This course is playing a few holes long, and even the short ones are feeling easy. My length helps but the important thing is to control it. The distance control is hard in this wind though. At least it was warmer today than yesterday.”
World Number 25 Dubuisson turned in a one under 35, and the Frenchman then birdied the first and struck his approach to five feet at the second for consecutive birdies before paring his way in.
“It’s a great score,” said the Turkish Airlines Open winner. “I played good today. It was more difficult than yesterday because the wind was in a different direction and it made some of the par fives difficult to make birdie on. My short game was good and that was important.”
Pepperell made a slow start to his second season at this level, but the Englishman has finished in the top 25 on his last two starts and three birdies erased the damage of a bogey at the 15th and double bogey at the fourth.
“I did pretty well today,” he said. “Hanging in there was what it was all about today.
“I shot level par which I think is pretty good today; it was so windy out there.
“No hole was easy, it seemed, so I’m very pleased to be in a share of the lead still heading into the weekend.
“The course showed its teeth today. It becomes fun when it is this tough as everyone else is finding it hard.
“It’s about hanging in there and not letting it get to you. I enjoy that type of golf. I’ve grown up playing amateur stuff in England on links in these sort of conditions, so I enjoy it.
“This is like an Open Championship out there. The sun is burning the course out and it’s windy, so it is tough.”
On a congested leaderboard, Stenson and Dantorp were part of a six-way tie for fourth a shot further back, along with Scots Stephen Gallacher and Chris Doak, Welshman Bradley Dredge and Thailand’s Thongchai Jaidee.
“I played better today than I did yesterday and of course I would have wished for a bit more,” said Stenson following a two under 70 that saw him double bogey the 17th after finding water.
