A showdown between the top two teams in the table at this stage of the season is a dream come true for the fans, TV companies and league authorities, and that scenario has come to pass in England and Germany this weekend.
First is at home to second in both cases, with Manchester United hosting Chelsea in a colossal clash in the English Premier League and Schalke at home to Bayern Munich in the Bundesliga.
United versus Chelsea has become the defining battle in the Premier League, with the two clubs having shared the title between them for the past five seasons, and their latest showdown has the potential to go a long way towards determining the outcome of the championship race.
This is not the all-or-nothing decider that Liverpool v Arsenal was in the old First Division in 1989 - a match that is unlikely to be surpassed for significance and spine-tingling drama - but it ranks with some of the key encounters of the Premier League era, such as United's 1-0 win at Newcastle that fuelled their remarkable comeback in the 1995-96 season and Arsenal's dramatic success at Old Trafford in 1997-98 that underpinned their surge past United to take the title.
If there is a winner tonight, that team would be odds-on for the title with only five games to play. But if it is a draw it would be all to play for, with United still ahead by just a point - and Arsenal would be right back in the hunt if they secure a home victory over Wolves later tonight, as that would put them only two points behind United.
The injury to Wayne Rooney is a blow for United. Rooney-driven United have been excellent at Old Trafford this season, winning 14 out of 16 in the league, failing to win only once when they have scored, while Chelsea's away form has become decidedly patchy.
Chelsea have won just three of their past nine away games and perhaps the reason for their fragility is Carlo Ancelotti's move to make them a more attacking team. Chelsea's goal average on the road is the highest since 2004-05, but already they have conceded more away goals than in any of the past five seasons - an openness that might make for a more entertaining game tonight, but will leave them open to United's thrusts.
United's effectiveness without Rooney is a matter for conjecture rather than hard-and-fast conclusions, though it is hard to escape the impression that he has become their driving force with his goals, vision and all-round work ethic. With that in mind, United on the handicap is the safe play, even though on form they rate well for the win at the odds available.
Chelsea, strangely, had a better record at Old Trafford during the years before they became serious title contenders. In the first 11 years of the Premier League, Chelsea had three wins, five draws and just three defeats away to United, but since Abramovich took charge they have lost on three of their six visits and won only once - at the tail-end of Jose Mourinho's first title-winning season, when the championship race was already over.
Since then, United have won three out of four at Old Trafford and the dip in Chelsea's away form this season suggests that trend is likely to continue.
While United and Chelsea have come to dominate the Premier League, the only constant in the Bundesliga is Bayern Munich, who remain the most powerful force in German football, but seem to face a different challenger each season.
This time Schalke are the team threatening to deny Bayern, who have won the title just once in the past three seasons, and there is a uncomfortable familiarity to the tale. Schalke's coach is Felix Magath, who won the double twice with Bayern, but was then sacked before coming back to haunt them by guiding Wolfsburg to a remarkable triumph last season. Now he is threatening to repeat the feat with Schalke, who are the nearly men - some would say chokers - of the Bundesliga.
Magath has toughened them up and they go into tonight's crucial showdown on a run of eight consecutive home league wins.
Bayern will be on a high, too, following their midweek comeback win over Manchester United in the Champions League, but they have wobbled recently in the league with two straight defeats. Magath certainly knows how to beat his old club, having defeated them 5-1 at home with Wolfsburg on this weekend 12 months ago and, as with United, the safe play is the hosts on the handicap.
Along with United, the best bets in the Premier League are Fulham for a home win over Wigan and Aston Villa on the handicap at Bolton.
The biggest doubt about Fulham is that the match falls between the two legs of their quarter-final tie against Wolfsburg in the Europa League, but their strength at home makes them a clear choice on form.
Bolton's seven consecutive failures to score against any team outside the bottom seven suggests they will struggle to match Villa, who have scored in 12 of their 15 away games.
Defeat for Aston Villa in their past 14 league meetings with Bolton: 1
Manchester United v Chelsea league clashes since the last away win: 9
Home league games without defeat for Birmingham City: 12
Top five bets
1 Manchester United on handicap Can stay out in front in their pursuit of a fourth straight title
2 Aston Villa on handicap March was poor, but tonight's visit to Bolton is a perfect opportunity to bounce back
3 Montpellier home win Surprise title contenders can maintain their challenge by beating Monaco
4 Fulham home win Tough opponents for Wigan, who have lost six of their last eight away
5 Atletico Madrid home win On a roll after a slow start, with six wins in their last seven home league games
Shortlist: Manchester United, Aston Villa, Crystal Palace, Watford, Sheff Wednesday, Swindon, Malaga, Montpellier, Fulham, Atletico Madrid.