Milan, Italy (My Sportsbook) - Defending champion Manchester United tied Inter Milan, 0-0, on Tuesday to extend its Champions League unbeaten run to a record 20 matches.

United last lost in the Champions League in the 2006-07 semifinals, compiling a 12-0-8 record since. The second leg of the round of 16 clash is March 11 at Old Trafford in England, when Manchester will try to end a streak of the last four defending champions being eliminated in the round of 16.

In Tuesday's other first legs, Thierry Henry scored late in the second half and Barcelona salvaged a 1-1 draw against Lyon, Robin Van Persie's penalty kick was enough for Arsenal to edge Roma 1-0, and Lisandro Lopez had two goals to take over the scoring lead in the tournament in FC Porto's 2-2 draw against Atletico Madrid.

United was the most impressive side in the first half against Inter, creating a handful of good scoring chances.

Cristiano Ronaldo had a header knocked deflected by Inter goalie Julio Cesar in the fifth minute, then drilled a one-hop free kick just wide of the right post in the eighth.

United's Ryan Giggs had the next chance when he did well to stay onside to get a one-on-one chance with Cesar. But from a tough angle on the left, Giggs drove a shot into Cesar, and the ball deflected wide.

Ronaldo followed with two more chances, again getting denied by a diving Cesar in the 28th off a free kick before firing a header inches wide seconds later.

Dimitar Berbatov had Manchester's last chance of the half, meeting a cross from Ji-Sung Park near the penalty spot, but he headed wide right.

Inter finally created its first scoring chance in the opening minutes of the second half, but Dejan Stankovic wasted the opportunity. Esteban Cambiasso picked out Stankovic with a cross but Stankovic got under a shot from 12 yards and fired well high.

Ronaldo disappeared early in the second half, but made a nice move on the right side to set up United's first chance after the break. He slid a pass through the six-yard box, but it was just out of the reach of Park and was cleared.

Cambiasso had Inter's last chance in the 82nd, nearly directly the ball over the line, but United goalie Edwin van der Saar, who has a 14-game shutout run in the English Premier League, snared the ball to keep it out of danger.

Ronaldo had one last chance to make up for his misses in the third minute of injury time, but his well-driven free kick was knocked down by Cesar, who had five saves.

Van der Saar didn't have to make a save in the match as United broke a tie with Bayern Munich and Ajax for the longest unbeaten streak in the Champions League.

At Lyon, Juninho scored off a free kick in the seventh minute to hand Lyon an early lead, but Henry answered with 23 minutes remaining.

Juninho, who scored twice in Lyon's 2-2 draw against Barca in last season's group stage, drove a free kick from near the left sideline past Barcelona goalie Victor Valdes.

Barca's Samuel Eto'o and Lyon's Karim Benzema traded shot off the post later in the first half.

Henry finally delivered the equalizer for Barca, which was coming off its first league loss since August, with a header from close range inside the left post.

At Arsenal, Van Persie got Roma goalie Doni going the wrong way to convert his penalty kick in the 37th minute. Van Persie picked out the bottom-right corner from the spot, and Arsenal held on to take an advantage into the second leg in Italy.

At Atletico Madrid, Maxi Rodriguez gave Atletico the lead in the third minute, and then Diego Forlan put Madrid back in front in the 45th, but Lopez answered both times to increase his scoring total to six goals.

Lopez scored his first goal in the 22nd, and added the game-tying goal in the 72nd.

On Wednesday, Liverpool visits Real Madrid, Juventus visits Chelsea, Bayern Munich visits Sporting Lisbon and Panathinaikos visits Villarreal.