MLS has made significant strides on many fronts since its introduction 91/2 years ago, but the league hasn't been able to make much progress when it has gone abroad for international competition. Losses by MLS clubs in small Central American countries and in Mexico, as well as an embarrassing defeat by a select team at Real Madrid this summer, have not helped the league's desire to join the world soccer establishment.

All of which heightens the importance of D.C. United's visit to Santiago, Chile, tonight for the second leg of its two-game, round-of-16 series with Universidad Catolica in the Copa Sudamericana.

United is the first MLS team to play in the 12-nation, 34-team South American tournament, providing a rare opportunity to elevate its own -- and its league's -- global profile.

The last time United played a meaningful match in Latin America was five months ago against Pumas in Mexico City as part of a regional event, the Champions Cup. The result was a 5-0 loss, equaling the worst setback in United's history and perpetuating the belief that MLS is still far behind many Latin leagues.

Prior to that game, United and Pumas had played to a series-opening 1-1 tie at RFK Stadium -- the same score as the first D.C.-Catolica meeting last week.

"It's going to be loud, it's going to be festive, it's going to be fun," midfielder Ben Olsen said. "When you look back at your career, these type of games are going to be remembered -- the trip, the fans, everyone against you. If you can win in a good atmosphere like that, it builds a lot of character for a team. I'm excited to see how we respond. We saw it in the Pumas game, so we got a taste of it, and we're champing at the bit to redeem ourselves."

United would advance to the quarterfinals against Fluminense (Brazil) or Banfield (Argentina) by winning outright tonight; by winning on penalty kicks following a 1-1 tie; or by earning a tie in which it scored at least two goals (away goals are the next tiebreaker after total goals scored).

However, the club will have to upgrade its performance after being outclassed for long stretches of the first meeting with the Chilean league co-leader.

"We have to realize, whatever happens in Major League Soccer, it's going to be different when you play international," Coach Peter Nowak said. "The mistakes we made against Colorado [in a 2-0 league victory last weekend] weren't punished, but we see a lot of times, even in the first game with Catolica, one mistake can cost us a goal. We cannot afford these same mistakes."

Catolica is considered a second-tier South American team, but in its first encounter with United, it displayed an attacking sophistication largely unseen in MLS. D.C. kept it scoreless -- and created a few chances of its own -- until Catolica took advantage of an unattended long ball just before halftime.

United reserve Jamil Walker's perseverance with about nine minutes left tied it before both teams missed golden opportunities near the end.

"We thought they were a good team, but definitely a beatable team," Olsen said. "We feel pretty confident we can come back with a result. The Pumas trip, we didn't know what to expect. I think we have a better chance in Chile. We feel more prepared, we feel we know what this team is about, their strengths, and we can adjust and adapt."