London:Defending champion Manchester United's first-half dominance failed to produce any goals on Tuesday at Inter Milan in a 0-0 draw in the first leg of the Champions League's last 16.
Barcelona and Atletico Madrid were also held to draws as Europe's premier club competition resumed after a two-month break.
Thierry Henry's headed goal salvaged Barcelona a 1-1 draw at Lyon, and Atletico twice threw away its lead and allowed FC Porto to claim a valuable 2-2 draw.
Arsenal was the only victorious side on Tuesday, beating AS Roma 1-0 on Robin van Persie's 37th-minute penalty.
Manchester United completed a record 20th consecutive Champions League match unbeaten, but squandered a string of chances at the San Siro in the first 45 minutes.
Cristiano Ronaldo had come close in the fifth with a header that was blocked by Julio Cesar, and the Portugal winger threatened with a couple of free kicks.
With Inter rarely emerging from its own territory, Cesar had to remain on constant alert, turning Dimitar Berbatov's header wide and using his legs to deny Ryan Giggs when the Welsh midfielder broke free after Nelson Rivas had been beaten.
Inter played better in the second half and could have taken the lead in the 47th, but Adriano made a poor connection with Esteban Cambiasso's cross and volleyed over.
Cesar prevented United from claiming a late winner by blocking Ronaldo's free kick with the last touch of the match.
"I hope it doesn't come back to bite us (not scoring)," United manager Alex Ferguson said. "We played very well. In the second half, for 10 or 15 minutes, they presented a bit of pressure which we expected but other than that we played very, very well, with good composure and maturity."
Lyon captain Juninho put the French side ahead in the seventh minute, scooping the ball over the head of Barcelona goalkeeper Victor Valdes.
The former Brazil midfielder's 42nd goal from a free kick since joining Lyon eight years ago wasn't enough to separate the French and Spanish league leaders.
Thierry Henry leveled for Barcelona in the 67th when defender Rafael Marquez flicked on Lionel Messi's corner from the right. No Lyon defenders picked up Henry's run at the far post and the striker scored a rare headed goal.
Arsenal wasted chances for a far bigger margin of victory as it edged Roma 1-0. Van Persie scored from the spot in the 37th after he had been tripped by Roma defender Philippe Mexes.
Nicklas Bendtner squandered two opportunities and Emmanuel Eboue was wasteful, while John Arne Riise almost equalized for Roma.
"There was room for more goals, that's the only regret from tonight," Arsenal manager Arsene Wenger said. "We kept a clean sheet, that's important, and I felt every time we got the ball we used it well."
The Gunners ran into trouble with Danish referee Claus Bo Larsen when they kicked off the second half with only nine men on the field. Defenders Kolo Toure and William Gallas were slow returning from the changing room and Toure got a yellow card when he tried to get into the field with the game in progress. Gallas entered later.
Lisandro Lopez scored both goals as FC Porto twice came from behind to draw at Atletico Madrid.
Pablo Ibanez misjudged a long ball in the 22nd minute and Lisandro ran in behind the Atletico defender to shoot under goalkeeper Leo Franco. The Argentina striker, who had a handful of chances in a match dominated by Porto, scored another in the 72nd for his sixth goal in seven European matches.
Maxi Rodriguez gave Atletico the lead in the third minute, and Diego Forlan scored Atletico's second in first-half injury time when Porto goalkeeper Helton let the Uruguay striker's shot slip through his hands.
"It's a very good result against a very good team. We will take a few lessons from this match for the return leg," Barcelona coach Pep Guardiola said.