The duo left their breakaway companions in the dust, showing remarkable finishing power on the final ascent to dislodge their rivals, cruising home in 2:40:07 after 67km of undulating racing.
The Ascendis-LCB team of Gert Heyns and Arno du Toit, who clocked 2:41:36, was next to reach the finish at the Zuurberg Mountain Village with Marco Joubert and Andrew Hill of TIB Insurance-Momsen third in 2:42:02.
Woolcock, coming off a win with Kruger at the three-day Winelands Encounter in the Western Cape last month, said the race was far from finished.
“The lead we have means very little in mountain biking terms and we will go into tomorrow knowing that we have to be cautious, while also trying to maintain the pressure on our rivals,” said the 34-year-old from Stellenbosch.
Woolcock said the nature of the course on the opening day played to their strengths as they were both good climbers.
“I might have the edge on the climbs, but HB is able to keep a higher tempo on the flats and rolling climbs.”
Woolcock said being in front was the best possible scenario.
“It’s always better to lead than to chase. I wouldn’t say it takes the pressure off, but it does mean we don’t have to force it.
“Tomorrow we will work to look after the bike because it’s better to lose a few seconds in a technical section than to try to close the gap after having a puncture.
“So it’s always a bit of a relief to have that buffer.”
Woolcock described how all the favourites were together as they hit the first major descent, and their sole focus was on making sure they didn’t have any mechanicals.
“We went into the first single-track and all the cross-country boys were very excited, but all I could think of was safety first – look after your tyres, look after your bike and yourself,” he said.
“Arno and Gert went screaming down the single-track and had gapped us quite a bit, but when we came around a corner, we saw that Arno had a puncture.”
The two teams joined forces as they headed towards the day’s first major test.
“On the climb just before the waterpoint, about 20km in, we saw Arno was taking a bit of strain, so we gapped them quite a bit,” explained Woolcock.
“But we knew it was too early to ride alone from there as there are a lot of flat sections before the final climb.”
After the waterpoint, two teams – Hill and Joubert and Chris Wolhuter and Craig Boyes of Imbuko Wines – rode up to the leaders and Woolcock said the workload was shared evenly at that point.
“There was nothing tricky or technical as it was jeep track and mostly open district roads, but we knew the last climb was going to be decisive.”
As soon as they started to climb Zuurberg Pass that linked the valley at the bottom with the hotel at the top, Kruger went clear at the front while Imbuko Wines started to falter at the back.
“HB had a gap of a few hundred metres and when I could see that Arno couldn’t respond, I attacked him and rode across,” said Woolcock.
“Once I got there, HB kept up the tempo to give me a bit of breather and we then worked together to keep the gap until the finish.”
Neill Ungerer and Yolande de Villiers of Dryland-Ultimate Cycling, who won the GR300 last month, finished in 3:02:26 to lead the mixed section.
Andrea and Steven Shirley of On Your Bike finished second in 3:25:46 with Roan Rossouw and Heather Slabbert of Totally Stoked third in 3:48:48.
Siska van der Bijl and Annie Davids of GZT-Ladies were the first women home in 3:45:44.
Riders will tackle the queen stage over 78km with 1 750m of climbing on Saturday.