(CNN) -- Manchester United returned to the top of the English Premier League with a 3-1 victory over in-form Tottenham on Saturday but the champions' title hopes suffered a blow with the news that top scorer Wayne Rooney may miss the rest of the season.
The England striker sat out the home win, which put United two points clear of Chelsea, with a groin injury suffered in training and he may miss the final two matches of the season.
England coach Fabio Capello will be hoping that United take no risks with the 34-goal forward, who will be one of his key players at the World Cup in South Africa starting in mid-June.
"I think he'll probably take two to three weeks to recover," United manager Alex Ferguson told match broadcaster Sky. "We'll try to get him back, he'll obviously be desperate to get back himself. We'll just have to wait and see."
Earlier this month, Rooney made a sooner-than-expected return from an ankle injury to play in the second leg of the Champions League quarterfinal against Bayern Munich, then missed the 0-0 draw with Blackburn before a below-par outing in the 1-0 win over Manchester City that kept his side in the title race.
United face mid-table Sunderland and Stoke in the climax to the season as the club seek a fourth successive league crown, while Chelsea hosts Stoke on Sunday before a trip to Liverpool and a home clash with lowly Wigan.
Tottenham, who upset third-placed Arsenal and Chelsea in the two preceding matches, have not beaten United since 1989 and have not defeated one of the "big four" away from home in 66 matches.
Harry Redknapp's team still retained fourth place in the table as Manchester City drew 0-0 at Arsenal in Saturday's late match.
The Londoners looked like matching United at Old Trafford when defender Ledley King equalized in the 70th minute, but Portugal midfielder Nani snatched victory for the hosts with a delightful chip on 81 and then won a penalty for Ryan Giggs' second spot-kick of the game five minutes later.
The 36-year-old Giggs had never scored a penalty in his near 600-game career for United, but coolly took over Rooney's duties in the 58th minute after Benoit Assou-Akotto brought down Patrice Evra in the box.
United lost Evra to the lingering effects of his pre-match illness and winger Antonio Valencia went off with injury, while Spurs rallied with the return of England midfielder Aaron Lennon from long-term injury as a substitute.
Defender King headed in Gareth Bale's corner as United fullback Rafael strayed from his position on the post and could not clear the ball to give the visitors hope of a point.
But Nani raced onto substitute Federico Macheda's pass to beat goalkeeper Heurelho Gomes with an exquisite finish, and the Brazilian was again beaten by Giggs after a clumsy challenge from behind by Wilson Palacios.
Manchester City trail Tottenham by a point in the battle for the fourth Champions League place, with the two teams to meet in their penultimate game of the season on May 5.
City boss Roberto Mancini surprisingly left Emmanuel Adebayor on the bench after the Togo striker's ill-advised goal celebrations in front of his former club's fans when the teams last met in the league in September.
Adebayor made an impact when he came on in the second half, but the match was most notable for a season-ending shoulder injury suffered by City's Republic of Ireland goalkeeper Shay Given that allowed Gunnar Nielsen to become the first Faroe Isander to play in the Premier League.
The 23-year-old was largely untested as Arsenal's faint title hopes were finally extinguished, with the Londoners now seven points behind United with two matches left.
Nielsen may have to fill in for the rest of the season, with Given's deputy Stuart Taylor injured and England international Joe Hart on loan at Birmingham.
City next take on sixth-placed Aston Villa, who can keep their own Champions League hopes alive with victory at home to Midlands rivals Birmingham on Sunday.
West Ham moved six points clear of the relegation zone with a 3-2 win over fellow strugglers Wigan that keeps Gianfranco Zola's team in the top flight for another season.
Captain Scott Parker struck a 77th-minute winner from long range as West Ham recovered from an early own-goal by United States defender Jonathan Spector, with Brazilian striker Ilan and Czech midfielder Radoslav Kovac putting the London side 2-1 up at halftime.
Colombia striker Hugo Rodallega leveled seven minutes after the interval with a bundled effort as Victor Moses flicked on a cross from first-goal provider Ben Watson, but Kovac headed against the bar before midfielder Parker celebrated his return from suspension with a fine winner.
The result sent third-bottom Hull down to the second division after the Yorkshire side lost 1-0 in an ill-tempered home clash with Sunderland that saw both teams reduced to 10 men.
Darren Bent put Sunderland ahead in the seventh minute from close range after strike partner Kenwyne Jones headed Alan Hutton's cross into his path for the England World Cup hopeful's 25th goal this season.
Hull should have leveled after the club's former defender Michael Tuner brought down Geovanni, but Jimmy Bullard hit the post with his penalty attempt.
Hutton was sent off just before halftime following an ugly exchange with Hull striker Jozy Altidore, which saw the Scot receive a headbutt after throwing the ball in the face of the United States international, who was also red-carded.
Wolverhampton Wanderers will be safe for a second season in the Premier League if fellow promoted side Burnley fail to beat Liverpool on Sunday, having moved eight points clear of the second-bottom side with a 1-1 draw at home to Blackburn.
Blackburn captain Ryan Nelsen put the visitors ahead in the 28th minute, with the New Zealand defender diverting in Morten Gamst Pedersen's corner, but substitute Sylvain Ebanks-Blake headed an 81st minute equalizer from Stephen Ward's cross.
Relegated bottom club Portsmouth came from two goals down to earn a 2-2 draw at Bolton, as Ivory Coast striker Aruna Dindane netted a second-half double for the FA Cup finalists to cancel out first-half efforts by Kevin Davies and Ivan Klasnic.