In a slight kick to the finish in Rembau, Mareczo out sprinted Juraj Sagan (Tinkoff) and Dylan Page (Team Roth) to claim the stage win.
“It’s been a bit difficult for me to take part in the sprints early on because there have been a few crashes, but today finally I managed to make it," Mareczo said.
“Today there were more KOM primes than usual. It wasn’t easy to hold the place but my teammates kept me in the main group. In the last few corners in the run in to the finish, I stayed in the first three so I was in the right position for sprinting.”
Janse van Rensburg moved into the race lead after Miguel Angel Lopez (Astana) suffered a puncture with six kilometres to go. In the final 500m, Janse van Rensburg managed to stay upright in the 180 degree bend crash chaos, but lost his chain and could not contest the sprint.
"I have yellow now but it feels bitter sweet, taking the jersey in such a way and also losing my chance to go for the stage win. Songezo Jim and Adrien Niyonshuti sat in the breaks today and put pressure on the other teams to chase. The rest of the team did a great job to get me in a good position for the sprint.
"Now we need to defend the jersey for the final two days. The bunch is really getting aggressive now, so I think it’s going to be quite a big fight tomorrow, and there is quite a climb early on. So we are going to have to be top of our game coming out,' he said.
Peter Sagan's brother, Juraj was happy with second place.
“I'm always helping others. But today I had the green light because our sprinter Michael Kolar had a flat tyre with 7km to go. This is my first international result as a pro," Sagan said.
Andrea Guardini decided not to contest the sprint.
“I was a bit full gas at 15km to go and I took the decision to leave this stage for rest and try to win another stage – tomorrow or the last stage. This was harder than the other stages," he said.
The stage was characterised by three earlier breaks. Seven riders tore away in the opening kilometres, caught after 80km of racing by a UnitedHealthcare driven peloton. A six rider break then formed but ultimately Tanner Putt (UnitedHealthcare) attacked alone with 45km to go. Dimension Data with the stage win in mind reeled in Putt on the final climb.
Janse van Rensburg leads Jaramillo (UnitedHealthcare) by 11 seconds and Lopez by 12 seconds. Australia's Lachlan Norris lies in sixth place, 22 seconds off the pace.