With top-flight and European glory still a possibility for Zinedine Zidane's side, victory over a team who beat them in January's reverse fixture boosted their double hopes as Ronaldo surpassed 400 goals for Real Madrid.
The opener, which arrived after 10 minutes, had more than a hint of controversy about it as Nacho – in as one of five changes from the Champions League semi-final second-leg loss to Atletico Madrid – stroked home a quick free-kick as Sevilla were busying themselves arranging a defensive wall.
Jorge Sampaoli and his team were furious with referee Alberto Undiano, who waved away their protests as Nacho celebrated just his third LaLiga goal.
After Stevan Jovetic had struck the post, the hosts moved further ahead when Ronaldo tapped in from James Rodriguez's saved effort.
Jovetic also hit the crossbar and was thwarted by Keylor Navas before the break, but finally got his reward by pulling a goal back four minutes into the second half.
However, Zidane's men – aided by the introduction of Casemiro, who provided a steadying influence – wrapped it up late on through Ronaldo's stunning strike, with Toni Kroos' goal putting the seal on three crucial points with title rivals Barcelona beating Las Palmas by the same score.
In the fifth meeting between these two sides this season, Vitolo tested Navas with an early low strike that the goalkeeper spilled before gathering at the second attempt.
Opposite number Sergio Rico also had a heart-in-mouth moment when he was slow to react to Alvaro Morata darting in behind the defence, but he recovered to smother at the forward's feet.
The young goalkeeper was oblivious to Nacho's quick-thinking set-piece soon after, though, as Madrid moved in front.
Jovetic's powerful first-time shot rattled Navas' left-hand upright in the 20th minute to send a timely reminder of the visitors' threat.
But they were the architects of their own downfall for the second, as Matias Kranevitter conceded possession on halfway, with James darting into the area and seeing his shot palmed into the path of a gleeful Ronaldo.
Madrid were almost made to pay for a lapse in concentration at the back when Jovetic lifted a chip onto the crossbar, with Navas rooted to the spot.
Remarkably Jovetic still had time to see another chance go begging before half-time, with Navas – rather than the frame of his goal – keeping out the former Manchester City striker this time.
Madrid had clearly failed to heed Jovetic's three warning shots and early in the second half he found the net with a cool finish from Vitolo's lay-off.
With an air of angst suddenly falling over the Bernabeu, Casemiro was brought on to add some defensive solidity to the hosts' midfield and it did help to stem the tide.
It was not until 20 minutes into the second half that Rico was forced into a save, with Ronaldo's free-kick from an acute angle sending the keeper flying to his left.
The tension was lifted when Ronald sent a superb left-footed strike beyond Rico with 12 minutes remaining and Kroos turned in from close range soon after to add gloss, with Madrid knowing a win in their game in hand against Celta Vigo on Wednesday will leave them with one hand on the trophy.
Key Opta stats:
- Neymar scored his first away hat-trick for Barcelona in all competitions.
- The last Brazilian to score an away hat-trick in LaLiga was Ricardo Oliveira for Real Betis against Athletic Bilbao in February 2005.
- Lionel Messi has played more LaLiga away games without scoring against Las Palmas than against any other opponent (two).
- Luis Suárez has scored in each of his last four LaLiga games against Las Palmas (six goals).
- Neymar has the second-most assists in the top five leagues in all competitions (20), after Tottenham's Christian Eriksen (21).