Paris, September 18:

Manchester United began their European Champions League title defence with a damp squib on Wednesday as wily Spaniards Villarreal held them 0-0 at Old Trafford, while Arsenal and Celtic also drew.

United similarly failed to batter down the same rivals home and away three seasons ago — and subsequently saw their group hopes embarrassingly sink without trace. Celtic took

a leaf out of Uinted’s book

as they could only manage another scoreless showing against Danish minnows Aalborg.

United fans welcomed back Cristiano Ronaldo from injury but the Portugal winger was unable to oblige with a match-winning contribution after rising from the bench.

United had won their previous 12 home matches in the tournament going back to Villarreal’s last visit — but Ronaldo and company drew a blank.

But the experience of 2005, when a loss to Benfica ended United’s interest early, will serve as a timely reminder not to count chickens ahead of a double-header with Celtic, who actually beat the English Premiership champions in a group match in 2006.

Aalborg, meanwhile, frustrated the Celts, who missed a first-half penalty when Barry Robson saw his effort saved. The visitors’ Michael Beauchamp was wrongly red-carded in a case of mistaken identity for a foul on Georgios Samaras, but Aalborg held on for a precious away point.

Arsenal needed a late William Gallas equaliser to salvage a 1-1 draw against Dynamo Kiev in their Group G opener but at least they ended a three-match losing run in Ukraine. Defeat loomed again after Ismael Bangoura stroked home a second half penalty but skipper Gallas struck two minutes from time. Group rivals and two-time champions Porto saw off Turkey’s Fenerbahce 3-1 after early goals from Lisandro Lopez and Lucho Gonzalez had put the hosts firmly in the driving seat.

In Group F, four-times winners Bayern Munich thanked a solitary goal from Belgian defender Daniel Van Buyten for a valuable 1-0 victory away to Steaua Bucharest and French champions Lyon thanked a late goal from Karim Benzema as they recovered from 2-0 down to draw with Italy’s Fiorentina.

In Group H, two-time champions Juventus returned to the event after a two-season absence with a 1-0 home triumph over UEFA Cup winners Zenit St. Petersburg, Alessandro Del Piero netting a magnificent freekick. In the same group, nine-times winners Real Madrid cruised past Belarus debutants BATA Borisov 2-0 with Sergio Ramos and Ruud van Nistelrooy on target in either half.