The 21 year-old, who was raised in Bath, Somerset, carded seven birdies and one double-bogey on a fine morning in south Buckinghamshire.
She held a three-stroke lead over South African Ashleigh Simon with two rounds to play.
Simon was the only other player in the field to score below par on the first day after a swirling breeze picked up for the afternoon starters.
Simon was in the fifth last group out at midday and coped admirably with the changeable wind and sloping greens. The 22 year-old, who won the Portugal Ladies Open on the Ladies European Tour in May, carded four birdies and two bogeys in her round.
Zuel, in her third season as a member of the LET, broke her title duck at the Terre Blanche Ladies Open on the Ladies European Tour Access Series in March, but it would be a dream to win on her home soil this week.
Zuel said: “I haven’t really played that much this year, one week on, one week off, so I thought I’d come here just to keep the flow going and I’m enjoying it. It’s been good.”
After tying for 36th at the Aberdeen Ladies Scottish Open presented by EventScotland at Archerfield Links last week, she said that she hadn’t been working on anything in particular coming into the tournament: “The same as usual; it all just came together.”
Hazlemere is where world number one Luke Donald learned his game in his formative years and set out over rolling hills near the Chilterns, the course is an equal test of game and fitness.
“It’s quirky but in really good condition so I really enjoyed it,” Zuel said. “I made the putts and hit it pretty solid so it all came together nicely.”
Simon, who is ranked 20th on the LET’s Henderson Money List after 13 tournaments this season, said that the fast and undulating greens were the sternest test.
“It’s very tricky: you’ve got to hit them in the right spots and you can’t be aggressive with them because if you are, before you know it if you just miss the hole, you give yourself a long one coming back. You’ve got to try and take them when you can and lag them up to the hole,” she said.
Simon is staying with a great aunt nearby this week, hoping to carry some momentum through from the recent Ladies Irish Open, where she tied for sixth and the Aberdeen Ladies Scottish Open, where she tied for fifth last week, to next week’s Ladies European Tour event in Austria, followed by events in Prague and Spain.
“It’s carrying the momentum from the last three weeks into the next three. I was in the UK and I like to get into a bit of momentum,” she said.
“I hit it really good on the back nine and had opportunities on every hole but only made two, so you’ve got to stay patient. It played tough this afternoon. The wind really picked up on the back nine and it was swirling. I stood on a tee and it was downwind and then I hit it and it was opposite. Coming down the last nine I had a few opportunities and then I hit the pin on 18, so I couldn’t miss that one.”
A group of six players finished two strokes further back on level par 70. They were Marjet van der Graaff and Marieke Nivard of the Netherlands, Spain’s Maria Beautell, Scotland’s Heather MacRae along with Welsh duo Sahra Hassan and Katherine O'Connor, who is an amateur.
Australian Karen Lunn opened with a 74 and she said: “I played well; I just didn’t putt very well. The greens are very tricky, but I hit the ball well.”
The second round begins at 8.30am on Thursday, following which there will be a cut to the leading 25 players and ties. Those who are successful will contest the final round on Friday, competing for a first prize of €3,387.50.