This Fight Never Stops, Ronaldo scores HAT-TRICK, Messi scores HAT-TRICK

A day after Ronaldo threw down the gauntlet with a hat-trick for Real Madrid in a 6-1 thrashing of Galatasaray, prolific Argentine Messi responded with three goals in Barcelona's 4-0 Group H romp at home to Ajax Amsterdam.

 Lionel Messi stole Cristiano Ronaldo's thunder again by plundering yet another hat-trick for Barcelona and Basel ruined Jose Mourinho's Champions League return with a shock win at Chelsea on Wednesday.

Former champions Milan and Porto began the group phase with victories but last year's runners-up Borussia Dortmund suffered a jarring defeat at Napoli after being reduced to 10 men and having manager Juergen Klopp exiled to the stands.

A day after Ronaldo threw down the gauntlet with a hat-trick for Real Madrid in a 6-1 thrashing of Galatasaray, prolific Argentine Messi responded with three goals in Barcelona's 4-0 Group H romp at home to Ajax Amsterdam.

Whatever magic Ronaldo conjures, Messi always seems to have a riposte, soaring to ever greater heights in the ongoing duel between Europe's two most deadly marksmen.

Messi went through his repertoire, breaking the deadlock with a curling free kick after 22 minutes, running in his second 10 minutes into the second half and, after Gerard Pique had also got in on the act, completing his hat-trick with a clinical finish 15 minutes from time.

His latest exploits made him the first player to score four hat-tricks in the Champions League and took his overall tally to 62 goals in 80 matches in the competition. Ronaldo, three times beaten to the World Player of the Year award by Messi in the last four years, has 53 goals in 93 games.