Tottenham Hotspur will seek to re-open old wounds when they face Premier League leaders Manchester City on Sunday in a fixture that has traditionally provided them with rich pickings but this time will offer an acid test of their title ambitions.
The in-form north London club travel to the Etihad Stadium five points behind Roberto Mancini's City in third place and two behind second-placed Manchester United, who face Arsenal at the Emirates on what could be a pivotal day at the top.
With four of the top five playing each other on Sunday, fourth-placed Chelsea can add a little pressure on those above by beating Norwich City at home on Saturday.
Just over 20 months ago Tottenham beat City 1-0 on the penultimate match of the 2009-10 season in what was a shoot-out for fourth place and Champions League qualification.
That result was reversed a year later when City erased that painful memory with a 1-0 victory at home to clinch a top-four place at Tottenham's expense.
Two clubs with proud histories but for so long chronic under-achievers have suddenly become rivals at the sharp end of English soccer -- shaking up the dominance of United, Chelsea and Arsenal when it comes to the battle for the title.
Until losing to City last season, Tottenham's visits to the sky blue half of Manchester were happy ones with seven wins resulting from their previous nine league trips.
That will count for little, however, on Sunday with City's expensively assembled squad having spent most of the season on top of the table and the memory of a 5-1 thrashing of Spurs at White Hart Lane in August still fresh in their minds.
Manchester United put eight past Arsenal at Old Trafford on that same day and a repeat of those results this weekend would leave the title race looking more like a two-horse race between Mancini's new pretenders and Alex Ferguson's champions.
Tottenham's form since that home defeat by City, however, has been remarkable with Harry Redknapp's side spearheading the London challenge with just one defeat in 19.
Two points dropped at home to Wolverhampton Wanderers last weekend tempered the fans' optimism somewhat, while City, who have stuttered of late, took advantage by grinding out a 1-0 victory at Wigan Athletic on Monday.
Despite Tottenham's surge, City defender Joleon Lescott believes United are the main threat.
"We need to focus on the next team behind us and at this moment in time that's United," Lescott, who will be without his defensive sidekick Vincent Kompany who is suspended, was quoted as saying by British media.
"As much as the points are vital to create a gap between us and Spurs, it's more important to pull away from United."
City's ability to cope without midfield powerhouse Yaya Toure while he is away on African Nations Cup duty, against the attacking threat of Tottenham will be vital on Sunday.
Spurs have struggled to score goals at home while grinding out wins against the likes of Sunderland and Everton but look ideally set up to profit from any extra space they are offered.
"We won't say it's all over if we lose but it's important we win this one," Tottenham captain Ledley King, who could return to defence after injury, told Sky Sports.
United kick off at Arsenal shortly after that game finishes and all eyes will be on Ferguson's team selection with Paul Scholes now back in contention after coming out of retirement and scoring in last week's 3-0 win against Bolton Wanderers.
"His experience in the dressing room and on the pitch will be a real boost to the lads. He isn't the most talkative guy but he'll lead by example," former United full back Dennis Irwin said of Scholes on the club's website (www.manutd.com).
Fifth-placed Arsenal could also include former talisman Thierry Henry, a player who often haunted United before leaving for Barcelona, in their side and will be desperate to revive their season and avenge the 8-2 humiliation at Old Trafford.
After a shock 3-2 defeat at Swansea City last week, another setback against United could leave Arsenal adrift in the race for a top-four slot, but manager Arsene Wenger prefers to treat the visit of United as a chance to make a statement.
"It is a massive opportunity because you feel we have given six points away in the last two games in a way that is unbelievable," Wenger said.
"It is time for us to wake up and be focused -- we have a good opportunity to do that against Manchester United."