Barcelona all but sealed qualification for the Champions League quarter-finals on Wednesday but last season's runners-up Bayer Leverkusen were eliminated and Valencia suffered a shock home defeat.
Barcelona drew 0-0 at Inter Milan to remain top of Group A, although the draw meant the Catalan side failed to set a record of 12 straight wins in European club competition.
They will join Manchester United and AC Milan, who qualified for the quarter-finals on Tuesday, if they earn a point from either of their final two games.
Leverkusen suffered a 3-1 defeat at Newcastle United, for whom former England striker Alan Shearer scored a first-half hat-trick to maintain the English side's hopes of qualifying for the last eight.
Valencia tasted defeat in front of their own fans in the Champions League for the first time when they were surprisingly beaten 3-0 by AS Roma in Group B, which remains tight after Ajax and Arsenal drew 0-0 in Amsterdam.
Barcelona were unable to better Ajax's record, set over two seasons of European Cup Winners' Cup games in 1987 and 1988, of 11 straight victories, but new coach Radi Antic will hardly care after securing a fine result at the San Siro.
Barcelona have 10 points at the top of Group A, with Inter on seven and Newcastle, who lost their first two games, back in contention on six points. The English side's next game is at Inter on March 11.
LIMP LEVERKUSEN
Newcastle recovered from losing their first three games in the first group phase to qualify and Shearer was in unstoppable form as Leverkusen subsided limply at St James' Park.
The former England captain opened the scoring with a diving header after five minutes, nodded in his second six minutes later and completed a hat-trick with an emphatic penalty nine minutes before the interval.
Leverkusen had squandered a golden chance to make it 2-1 but Germany striker Oliver Neuville's penalty was comfortably saved by Newcastle goalkeeper Shay Given, although Marko Babic did grab a well-taken consolation 17 minutes from time.
Group B is much tighter, with all four teams still in contention.
Ajax stay top on six points, the same tally as Arsenal but above the English club because they managed to score an away goal in drawing 1-1 at Highbury last week.
That could yet prove significant after Roma revived their challenge by blitzing Valencia, the 2000 and 2001 finalists, in Spain.
Before kick-off Valencia's 22-game unbeaten home record in the Champions League looked unlikely to be threatened by a Roma side who had lost all three previous matches in Group B.
But fit-again Roma captain Francesco Totti, with strikes after 25 and 30 minutes, silenced the Mestalla and Emerson grabbed a third for the Italians after 36 minutes.
Roma have three points, with Valencia on five, and both retain hope of reaching the last eight. But Ajax and Arsenal will qualify if they win their next matches, at home to Roma and Valencia respectively.
