Rarely has the UEFA Champions League looked so evenly balanced at this stage of proceedings. The only side to emerge with a two-goal cushion from their first leg two weeks ago were Liverpool, 2-0 winners over Inter Milan at Anfield. And while there was plenty of entertainment in those eight ties, they yielded a mere 18 goals, an average of only 2.2 per game.

The stage is set then for Europe's top sharpshooters to reclaim the limelight in this week's return fixtures. Steven Gerrard, Zlatan Ibrahimovic and Cristiano Ronaldo are currently setting the pace with five goals apiece. Lagging some way behind them on two is AC Milan's Kaka, who topped the charts last season with an impressive ten-goal haul.

After avoiding defeat a fortnight ago, three of England's quartet of representatives tuned up for their midweek commitments with some fine performances in the latest round of matches in the Premier League, with Manchester United, Chelsea and Liverpool all recording handsome wins at the weekend. Arsenal, meantime, required a last-gasp goal to hold Aston Villa at home.

The quarter-final line-up will not be complete until next week. Milanese rivals AC and Inter both have home ties against English opposition, with the Rossoneri getting first crack of the whip against the Gunners on Tuesday evening before the Nerazzurri entertain Rafael Benitez's men on 11 March.

The big match
Real Madrid-AS Roma (1-2)
After a worrying run of three consecutive defeats, including that 2-1 first-leg loss in Rome, Real Madrid returned to winning ways in Huelva on Saturday evening, snatching a 3-2 victory at the end of a lively encounter. And encouragingly for the Merengues, Brazilian talisman Robinho made a spectacular return after his injury lay-off. With the return leg against Roma very much in mind, Bernd Schuster opted to start the No10 on the bench. But when Robinho finally made his entrance 18 minutes from time, he turned the game on its head, scoring with his first touch of the ball only 16 seconds after coming on, and sealing the points for the visitors in the final minute.

Opponents Roma got back on the victory trail themselves, putting four unanswered goals past Parma to consolidate second place in Serie A and bolster their hopes of taking Real's scalp at the Bernabeu. On the downside for the Italians, Marco Cassetti dislocated his collarbone and will miss Wednesday's showdown, while Dutchman Arjen Robben is out for the Spaniards after picking up a serious ankle injury.

The rest
Exhausted by their recent punishing schedule, and struggling to match the goalscoring firepower of league leaders Inter, defending champions AC Milan have plenty to ponder ahead of their meeting with Arsenal. The Londoners have been running out of steam themselves in recent weeks, and, after a goalless stalemate in the first leg, Tuesday's decider could hinge on the smallest of details.

Having bagged 19 goals in La Liga so far this season, Sevilla are looking to Luis Fabiano to overturn their 3-2 defeat by Fenerbahce in Istanbul. Meanwhile, perennial French champions Lyon are hoping the return of inspirational defender Cris will give them the steel they need to keep the relentless Manchester United at bay. Even without several of their stars, Alex Ferguson's men were still far too good for Fulham as they cantered to a 3-0 win on Saturday.

Olympiacos, held to a 1-1 draw by Asteras Tripolis in the Greek Super League, face a similarly daunting task when they travel to London to take on Chelsea, who rediscovered their goalscoring touch with a 4-0 reverse of West Ham United on Saturday.

Schalke 04's preparations for their trip to Porto did not go smoothly as they fell to a 1-0 defeat at home to German Bundesliga leaders Bayern Munich. The men from Gelsenkirchen hold a slim 1-0 lead from the first leg and can expect a searching examination from the Portuguese hopefuls.

Last but definitely not least, Barcelona will be confident of completing the job they started in Glasgow 14 days ago by putting on a show against Celtic. And after his superb overhead kick in a 4-2 defeat to Atletico Madrid on Saturday evening, the Camp Nou is expecting nothing but the best from Ronaldinho.

Player to watch
After being sidelined with injury for seven long months, Lyon skipper Cris made a welcome return in the 1-0 defeat of Lille. The question is, after such a lengthy absence, will the big Brazilian be able to cope with the demands of two big games in the space of just three days?

The words
"We've played 13 games in 40 days since 13 January and that's verging on the impossible. Somehow we've got to dig up some energy from somewhere for the challenges ahead, starting with the match against Arsenal," Adriano Galliani, vice-president of reigning European champions AC Milan.

UEFA Champions League first knockout round, second legs:
Tuesday 4 March
Barcelona-Celtic (3-2)
Manchester United-Lyon (1-1)
Sevilla-Fenerbahce (2-3)
AC Milan-Arsenal (0-0)

Wednesday 5 March
Porto-Schalke 04 (0-1)
Real Madrid-Roma (1-2)
Chelsea-Olympiacos (0-0)

Tuesday 11 March
Inter Milan-Liverpool (0-2)