**Manchester United squandered a chance to regain the Premier League lead when it settled for a 0-0 tie with Blackburn on Sunday to remain behind Chelsea in the title race.
A victory would have put United a point ahead of Chelsea, but Antonio Valencia and Dimitar Berbatov both missed chances at Ewood Park.
Chelsea, which now leads the league by one point, has the chance to go four ahead of United by beating Bolton at home Tuesday.
Meanwhile Portsmouth reached the FA Cup final by beating Tottenham 2-0 a day after it was relegated from the English top flight.
It turned out to be a good day for Chelsea, which stayed ahead of United in the league title race and then found out it would face Portsmouth — in financial administration and down at the foot of the Premier League standings — rather than fifth-place Tottenham in the May 15 cup final.
In one of the biggest shocks of the season, extra-time goals by Frederic Piquionne and Kevin-Prince Boateng gave cash-strapped Portsmouth victory in a dramatic semifinal at Wembley.
While Portsmouth fans know their team will be playing in the League Championship next season, they also know they will be returning to Wembley where their team won the FA Cup two seasons ago, coincidentally under current Spurs coach Harry Redknapp.
United's lost opportunity against Blackburn could be costly.
"It's a blow, there's no question about that, and it makes it really difficult to win the league now," said United manager Sir Alex Ferguson, whose team is trying to become the first to win the league title four times in a row.
"That's a fantastic result for [Chelsea]. They will be really delighted at that and they have a home game against Bolton on Tuesday. They will be expected to win that of course. We needed to win today. We are a point behind Chelsea and they have a game in hand and that would take it to four points and it's a big gap."
Without 34-goal Wayne Rooney, who is sidelined with an ankle injury, United failed to dominate a mid-standings Blackburn side and its first clear chance did not come until just before halftime, when Valencia broke clear, only for Blackburn goalkeeper Paul Robinson to block his shot.
Berbatov had a good chance in the 80th minute when he was unmarked 15 yards out but shot straight at the keeper. Three minutes later, the Bulgaria striker, whose inconsistent form has made him unpopular with many of the United fans, fired wide from the edge of the area.
Deep into injury time, a half-chance fell to United right back Gary Neville but he pulled his shot wide with his weaker left foot.
Manchester City strengthened its hold on fourth place with a 5-1 victory over Birmingham.
Carlos Tevez stroked home a 38th-minute penalty and added a second when he touched in a header from Nedum Onuoha. Emmanuel Adebayor made it three before he and Onuoha scored further goals to move City on to 62 points from 33 games. Tottenham has 58 from 32.
Without injured striker Fernando Torres, Liverpool was held 0-0 at home by Fulham to lose more ground on City in the race for fourth. Rafa Benitez's sixth-place team now has 56 points from 34 games, with Aston Villa next on 54 from 32.
Wolves edged closer to safety with a 0-0 draw at home to mid-table Stoke and are now six points above the relegation zone with four games still to play.
Team Line-Ups :
Blackburn Rovers: Robinson, Jones, Givet, Salgado, Nzonzi, Samba (Nelsen 32 ') Grella, Pedersen, Olsson (Diouf 70'), Emerton (Dunn 45 '), Kalinic
Manchester United: Van der Sar, Vidic, Ferdinand, O'Shea (Evra 78 '), Neville, Scholes, Nani, Giggs (Gibson 57'), Valencia, Macheda (Park 65 '), Berbatov