Update: 8:03AM A massive second-half fightback wasn't enough for the Blues, who lost 39-36 to the Lions in Johannesburg despite scoring five tries to three.
Down 17-0 at halftime and 23-3 with less than half an hour remaining, the Blues found their attacking verve too late as they suffered a third loss from four Super Rugby games. They only consolation was securing two bonus points.
While the Blues return home from South Africa in 11th place, a Lions side expected to struggle this season are in fourth place with three wins from five games.
The boot of Marnitz Boshoff was decisive as the hosts lodged their first win over the Blues in seven meetings since 2006.
The first five-eighth landed five from six shots along with two dropped goals in a 24-point haul.
The Lions crossed through halfback Faf de Klerk and wing Coutnall Skosan late in the first spell after a scoreless opening 35 minutes.
Their other try was a contentious score to fullback Coenie van Wyk midway through the second half.
Van Wyk pounced on a loose ball after centre Deon van Rensburg appeared to lose possession forward in a tackle over the tryline by Blues wing Charles Piutau. South African referee Stuart Berry agreed with a TMO ruling that Piutau had stripped the ball backwards.
The try halted some Blues momentum which had begun through tries to Piutau and reserve halfback Bryn Hall as the game opened up.
Wing Frank Halai and centre George Moala crossed in quick succession to reduce the deficit to four points with 9min remaining.
Two Boshoff penalties made the result safe for the Lions before Blues fullback Benji Marshall capped a fine game with a 79th-minute try.
Former Kiwis rugby league captain Marshall produced a number of nice attacking touches in his first Super Rugby start. He also tackled and kicked soundly, though was caught out of position at times.
The visitors struggled at scrum time, where they were heavily penalised, while ill-discipline saw prop Charlie Faumuina and lock Tom Donnelly both spend 10 minutes in the sin bin.
Such indiscretions were costly, according to Blues captain Luke Braid, who says his team ultimately paid for a patchy start.
"We've had a problem with that in previous weekends. Two yellow cards, down by 20 points, it's hard to come back," he said.
"As a team, we've just got to learn how to get a bit tougher and play a bit clinical when the going gets tough."
Braid says Marshall showed glimpses of the talent he possesses.
"He's still got a lot to learn. He played pretty well today, running the ball around. He sparked some enthusiasm."
The Blues host another struggling side, South Africa's Cheetahs, in Auckland next week.