* Kagawa first Asian to score Premier League hat-trick
* Benitez ends tough week with Chelsea win
* Everton stay in hunt for top four
* Suarez scores hat-trick for Liverpool (Adds Liverpool win)
By Martyn Herman
LONDON, March 2 (Reuters) - Shinji Kagawa became the first Asian player to score a Premier League hat-trick with the Japan midfielder's stunning display inspiring runaway leaders Manchester United to a 4-0 win over Norwich City on Saturday.
Another capacity crowd turned up at Old Trafford expecting to witness Welshman Ryan Giggs make his 1,000th senior appearance for club and country but it was newcomer Kagawa, still a one-year-old when Giggs made his United debut in 1991, who stole the show as United romped 15 points clear.
He put United ahead on the stroke of halftime and scored two more goals after the break before Wayne Rooney's late screamer rounded off a victory that kept Alex Ferguson's side surging relentlessly towards a 20th English league title.
Despite the proximity of United's Champions League last 16, second-leg clash with Real Madrid on Tuesday, they fielded a strong lineup although Giggs was given a rare afternoon off.
Champions Manchester City can close the gap to 12 points with victory at Aston Villa on Monday but the most exciting issues left this season, barring a United collapse, appear to be the battle for the top four and the relegation scrap.
Chelsea leapfrogged Tottenham Hotspur into third place with Demba Ba's first-half goal earning under-fire manager Rafa Benitez's side a 1-0 win at home to West Bromwich Albion.
Interim boss Benitez, who criticised the club's fans in the week when he confirmed he would leave the club in May, was spared the anticipated barracking from the stands as Chelsea moved a point above Spurs who face Arsenal on Sunday.
"There were a lot of positives. The reception from the crowd was quite good. I wanted everybody to stick together," Benitez, taunted with one banner declaring him "The Interim One", said.
"You can see today the fans were behind the team."
Luis Suarez scored a hat-trick for Benitez's former club Liverpool in a 4-0 win at Wigan Athletic to move above Manchester United's Robin van Persie in the Premier League scoring charts with 21 and maintain his side's top-four hopes.
Everton also revived their chances of qualifying for the Champions League with a 3-1 defeat of visiting Reading to move to within six points of Tottenham - Marouane Fellaini, Steven Pienaar and Kevin Mirallas all on target.
Bottom club Queens Park Rangers capitalised on Reading's defeat, winning 2-1 at Southampton to leave Harry Redknapp's side four points adrift of fourth from bottom Wigan.
League Cup winners Swansea City avoided a Wembley hangover with a 1-0 home win over Newcastle United, Sunderland recovered from two goals down to draw 2-2 with visitors Fulham and West Ham United eased relegation fears with a 1-0 win at Stoke City.
Kagawa, whose first season at Old Trafford since signing from Borussia Dortmund started promisingly with a goal on his home debut but who has since been disrupted by injury, delighted Ferguson and the large United fan club back in Japan.
"It's brilliant for him. The lad is a good finisher and his second goal was so composed and an intelligent finish while his third was absolutely brilliantly taken," Ferguson told Sky Sports. "It has been a great day for him."
Ferguson said Giggs would reach his career milestone against Real Madrid on Tuesday.
"(He) will be involved against Real Madrid, no doubt about it," he said. United drew 1-1 in the first leg at the Bernabeu.
Robin van Persie teed Kagawa up to volley his first goal - and United's 900th in the Premier League - on the stroke of halftime and his two strikes after the break were assisted by Rooney who looked razor sharp.
Norwich rarely threatened a repeat of their victory over United earlier in the season and Kagawa's cool finish from Rooney's unselfish pass made it 2-0 after 76 minutes.
His hat-trick was completed three minutes from time when he ran on to Rooney's pass to clip the ball home and Rooney then turned finisher with a curler from 25 metres.
QPR's third league win of the season brightened Redknapp's 66th birthday although the former Spurs boss was angry about a newspaper report claiming his players indulged in late-night drinking sessions at a training camp in Dubai.
"A disgusting story full of untruths," Redknapp was quoted as saying by the BBC. "I know where the story has come from and it's someone trying to make problems for the club. I can be as sure as I can be that it came from a football agent." (Reporting by Martyn Herman, editing by Justin Palmer and Ken Ferris)