In a sparkling first half, the 22-year-old Portuguese made three of his side's goals in a devastating 11-minute spell.
The whole of the footballing world knows how good Ronaldo is, but this was Ronaldo at his best.
He virtually laid his side's first goal on a plate for Ji-Sung Park after 14 minutes.
Picking the ball up on the left wing just inside the Wanderers half from Wayne Rooney's header, Ronaldo raced away down the flank.
When he reached the byline, he cut across towards the penalty area and as Bolton defender Tal Ben Haim came over to meet him, Ronaldo cut the ball back to Park, who scored with a low right-foot shot from 12 yards.
If that was good, Ronaldo's part in United's second goal, three minutes later was even better.
Standing in his own penalty area, Ronaldo collected the ball, played a one-two with Rooney and set off on another surging run.
With Rooney to his left and Ryan Giggs to his right, Ronaldo kept on running through the middle until he reached the edge of the Bolton box.
Ronaldo opted then for Rooney to his left, releasing the ball to perfection and watching as the England man scored with a glorious right-foot chip, waiting until Bolton goalkeeper Jussi Jaaskelainen was almost up to him before lifting the ball over the Finn and into the net from ten yards.
Ronaldo mesmerised Bolton's defenders for the third goal, hypnotising them as he jinked and turned before driving in a shot from 20 yards.
Jaaskelainen parried the effort as he dived across his line, but Park followed up to tuck away the rebound from close range.
Ronaldo had been off the field for four minutes when United made it 4-0 with 20 minutes to go, but ironically it was his replacement, Alan Smith, who played a key part in the goal.
Nemanja Vidic's headed clearance from the edge of the United penalty area fell to Smith midway inside his own half.
Smith looked up and played the perfect through-ball to send Rooney racing clear.
With only Jaaskelainen to beat, Rooney executed the most difficult of finishes, rocking back to smash the ball right-footed past the Bolton goalkeeper from 12 yards and into the top corner of the net.
Bolton scored their consolation effort from the penalty spot three minutes from time.
Vidic was adjudged to have lent on Abdoulaye Faye in the United box and Gary Speed dispatched the penalty left-footed - the shot being partially stopped by goalkeeper Tomasz Kuszczak before going through his legs and into the net.
The only dark cloud for United was Gary Neville's eighth minute injury - the England defender limping off after falling badly in his attempt to clear the ball from Speed.
Neville suffered ligament damage to his right ankle and will be out for three weeks, missing England's next two European Championship Qualifiers.