Els recorded an eagle and seven birdies in a nine-under-par 63 in sweltering conditions on the Munchen Eichenried course.
It was the 43-year old four-time Major winner’s lowest round since finishing runner-up to Ian Poulter in last November’s WGC–HSBC Champions event in Shenzhen, China.
“Today was like walking out of the torture chamber that was last week’s US Open and walking out onto a nice parkland golf course,” said Els.
“Of course, you still have to hit the shots but I felt like I was starting to swing the club last weekend at Merion, and I’m lucky enough I could bring it here to Munich.”
Four players — German hero Martin Kaymer, England’s Matthew Baldwin, Sweden’s Alex Noren and Dutchman Robert Jan Derksen — are tied in second place on eight under par.
Byrne even found himself being asked for an autograph soon after Els had signed his scorecard.
Byrne began caddying for Els at the start of the season after earlier carrying the bag for the likes of his fellow double US Open winner and countryman Retief Goosen. Byrne was on the bag when Noren won the 2009 European Masters and he helped steer Italy’s Edoardo Molinari to victory in the 2010 Johnnie Walker Championship.
Molinari’s success in Scotland led to him being chosen hours later as a Ryder Cup ‘wild card’ pick.
Two years ago, England’s Tom Lewis captured the 2011 Portugal Masters title in only his third Tour event with Byrne on the bag.
“Colin is a brilliant caddy and he brings a lot of weight and experience to my bag,” said Els.
“He also brings calmness when I need to be calmed down. So I just like him, a lot. He’s a good guy and we have a nice relationship.”
Peter Lawrie and David Higgins are the best of the four Irish, shooting five-under-par 67s, both starting and ending their rounds with birdies.
Lawrie holed a 15-foot birdie putt to open his round and then ended sinking a six-footer at the last.
“Five under par is a good start and looking at the leaderboard you need to shoot a decent score just to keep in touch,” he said.
Lawrie has returned to competition after a fortnight’s break beginning a run of four tournaments in four weeks, and hopefully five if he qualifies next Monday at a British Open qualifier at Sunningdale.
Lawrie is among five Irish in the 96-player field looking to secure one of the dozen spots into Muirfield.
And Lawrie has called on Irish Open organisers to ‘take a leaf out of the book’ of BMW International Open officials and set-up the Carton House venue to produce a bountiful bag of birdies.
Lawrie got his first look in seven years at Carton House last Thursday, playing a practice round ahead of next week’s 57th staging of the Irish Open.
“Carton House is in very good condition, but then I don’t know what they are going to do about the rough as it was very high when I played it,” he said.
“Hopefully, organisers can take a leaf out of the book of this week’s organisers and set it up so the fans will get to see plenty of birdies.”
Shane Lowry capped his round of 69 with a sixth-hole eagle.