Real led through Nacho’s controversial free-kick before Ronaldo pounced on a rebound to double their lead.
Stevan Jovetic replied after the break, but Ronaldo’s sensational second strike, his 401st for Real Madrid, and Toni Kroos’ late goal sealed victory.
Real Madrid stay in second place behind Barcelona who beat Las Palmas 4-1.
Reigning champions Barcelona keep hold of top spot courtesy of their head-to-head advantage.
But Real have a game in hand and need four points from their final two matches to lift their first title since 2012.
The home side found themselves in front after 10 minutes courtesy of Nacho’s quick-fire free-kick.
When Marco Asensio was fouled outside the box, referee Umdiano Mallenco awarded the free-kick and with the Sevilla defenders still remonstrating, Nacho seized the initiative striking the ball into an unguarded net.
But Ronaldo will take the plaudits, scoring his 400th and 401st goals for Real Madrid in just 391 appearances, and drawing level with Jimmy Greaves on 366 as the all-time top-scorer in the top five European leagues.
The 32-year-old’s tap-in from six yards was one of the easier of his goals but his second – a strike from a tricky angle just inside the box – matched the occasion.
Sevilla had their chances in the first half – Stevan Jovetic twice hit the woodwork before forcing goalkeeper Keylor Navas into a top-class diving save.
Former Manchester City striker Jovetic pulled one back for the visitors with a fabulous finish minutes after the break.
But Zinedine Zidane’s side held off the nerves and will now play their game in hand at Celta Vigo on Wednesday.
Sevilla stay fourth, despite having won just three of their last 11 matches, and need one more point to make certain their qualification for next season’s Champions League.