Veiby took charge early on and collected three stage wins on his first FIA World Rally Championship start since February last year.
The Volkswagen Polo GTI R5 pilot entered the final Umeå Sprint test 14.8sec ahead of his rival, but his day’s work came undone when a stall cost 20.3sec.
That handed Mikkelsen a surprise lead and he ended the day with a 4.1sec advantage in a Škoda Fabia Rally2.
"We had a good day and didn't take too many risks this morning,” said the leader. “We tried to step it up a little bit for the second pass and I think we managed to improve, but there’s still a long way to go," he added.
Veiby was quick to display his frustration at losing out on top spot so late in the day.
"I stalled the car in a junction and then it wouldn't restart - I was sitting there for so long,” explained the 25-year-old. “It was such a good day and it's a big shame that this happened here. At least now he can clean the road for us tomorrow!"
Mikkelsen’s Fabia team-mate Nikolay Gryazin held the final step of the podium, with Estonian driver Georg Linnamäe just 1.9sec behind. The Polo youngster surprised many with his new-found pace and even snatched a handful of top-three stage times.
M-Sport Ford star Jari Huttunen was involved in the lead battle, but tumbled down the order when he stalled his Fiesta on the start line at Kamsjön. He ended a tiny 1.9sec down on Linnamäe, whilst Volkswagen stalwart Egon Kaur was another 24.6sec behind in sixth.
A number of drivers fell victim to Sweden’s punishing stages. Emil Lindholm rolled his Fabia on SS2, whilst Marco Bulacia suffered a similar fate later in the day at Kamsjön. Both are expected to restart on Saturday.
Mattias Adielsson and Josh McErlean both retired in the afternoon after getting their cars stuck on snowbanks, whilst Spain’s Alexander Villanueva crashed his Citroën C3 on SS1.
- Full coverage from Rally Sweden is available on WRC+ All Live here, including every stage broadcast as it happens as well as key interviews, features and expert analysis from the service park.
Finland
Italy
Hungary