Ronaldo struck twice in just over a minute to bring Madrid level in the tie inside 17 minutes.
Yet, the 10-time winners were forced to wait until 13 minutes from time to find the winner when Ronaldo’s dipping free-kick escaped the clutches of Diego Benaglio to find the bottom corner.
Madrid hadn’t overturned a first leg deficit in the Champions League in eight attempts stretching back 14 years to when coach Zinedine Zidane played for Los Blancos in a quarter-final win over Bayern Munich.
However, they roared back into the tie and were level as Ronaldo struck twice in 86 seconds.
Dani Carvajal replaced the much-criticised Danilo in Madrid’s only change from the first leg at right-back and the Spanish international’s deflected cross fell perfectly for Ronaldo to tap home the opener at the back post.
The two nearly combined for the second straight from the restart as another dangerous Carvajal effort was just cut out before Ronaldo could head home.
However, there was no stopping the three-time World Player of the Year from the resulting corner as his downward header found the bottom corner for his 15th Champions League goal of the season.
Wolfsburg’s disastrous start was compounded when star midfielder Julian Draxler limped off injured to be replaced by Max Kruse just after the half hour mark.
Yet, the Germans still managed to grow into the game as the opening 45 minutes wore on.
Luis Gustavo’s fierce long-range effort forced Keylor Navas into a decent save before Bruno Henrique squandered a huge chance to net the vital away goal as he hesitated in getting his shot off and Marcelo got back to block the ball behind.
Madrid started on the front foot again at the start of the second-half as Ronaldo saw a free-kick deflected wide before Benaglio was forced into a save to prevent Joshua Guilavogui turning a cross into his own net.
The hosts were convinced they had gone ahead for the first time in the tie when Sergio Ramos’s header came off the inside of the post and rolled along the goal line, but Hungarian referee Viktor Kassai adjudged the ball hadn’t crossed the line.
Wolfsburg continued to pose the threat of an away goal as Vieirinha fired wide before Dante’s downward header was held by Navas.
However, Ronaldo finally struck the decisive blow when his free-kick from 25 yards skidded off the wet turf and beyond the despairing dive of Benaglio to seal his 37th hat-trick for Madrid.
The Swiss ‘keeper then kept Wolfsburg in the tie with brilliant saves from Karim Benzema and Jese Rodriguez to set up a grandstand finish.
But Madrid’s experience told in the dying stages as they comfortable saw the game out to match Barcelona’s record run of six semi-finals between 2008 and 2013.
