Luke Littler overcame a chorus of boos in Liverpool to strengthen his grip on a Premier League play-off place with an impressive 6-1 win over Jonny Clayton. Manchester United fan Littler, 19, was booed throughout the night on Merseyside, but he kept his cool to claim his fourth nightly win in week 12. The world champion saw off Luke Humphries 6-2 in the quarter-finals, but was pushed to the limit by Michael van Gerwen in the last four. With the top four in the Premier League table going through to the finals night, Clayton leads the way overall, three points clear of second-placed Littler, who is 15 ahead of Gian van Veen in fifth. Clayton and Littler are clear of the rest with four league-phase nights to go before finals night at London's O2 Arena on 28 May. When comparing his reception in Rotterdam last Thursday to the one he got in Liverpool, Littler said: "Rotterdam was way louder than this tonight. "There was a little bit [of booing] but this week was nothing compared to last week.…