The fearless forward wowed with her attacking flair as Chelsea opened up a ten-point gap on their rivals with a 3-1 win on Sunday.
Her second hat-trick at Stamford Bridge this season, watched by a crowd of more than 20,000, denied United hopes of a point.
And James prompted pantomime jeers from her old club’s fans by marking her opening goal with a jubilant jog to the away end with smiles in response to the boos.
After the game, Blues chief Hayes said: “I think she enjoyed that. I don’t mind these things in the women’s game. You give someone stick, you have to get it in return right?”
“I’ve never seen a player like Lauren do the things she does individually.
Read More Football Stories
“She’s so explosive, but she’s got a left and a right foot, that’s the thing.
“Often you play against players, and you know they’ve got strong sides, but for Lauren I think she can do it on both feet.
“I thought it was a brilliant, brilliant performance from the whole team.”
Of her celebration for Chelsea’s opener following the earlier away end boos, James admitted she joined silencing the jeers.
She told BBC Sport: “Yes for sure (it was nice to silence them).
“But for me it’s just about focusing on what I can do and silencing anyone who is hating as well.
“I’ve got to focus on myself and helping the team.”
Chelsea’s victory maintained their unbeaten run against the Red Devil in the WSL.
The leaders have now claimed seven wins in eight WSL meetings with their foes.
And James took her league goal tally to 10 in 10 games so far this term.
Hayes added: “I was impressed with her whole performance. I think focusing on those qualities (of her hat-trick) would sell it short.
“She’s shown her qualities as a nine and a 10. She carried out the game plan and her role in that game plan to perfection.”
On of her side’s overall display Hayes said: “One of the things we’ve been talking about in the background – and led by the players and driven by them – is what is a Chelsea standard?
“I think we showed that. This was our best performance of the season (so far) It looked like the standards we’ve set, but also, it was brave.”
Chelsea flew out of the traps taking a fifth-minute lead with James firing past Mary Earps moments after being booed by away fans while taking a corner kick.
And she doubled their lead, pouncing on Natalie Bjorn’s long ball to slot in her second with 22 minutes gone.
United mounted a fight-back with Geyse causing problems on the counter and teeing up Hayley Ladd’s smashed finish to make it 2-1 near half-time.
They pushed hard for a leveller with Toone seeing a scuffed effort cleared from the box.
The visitors were angered to see spot-kick appeals denied after Leah Galton fell in the penalty area after battling for the ball with Ashley Lawrence.
Skinner said: “I think it was a big decision in the game and I’ve spoken to the referee and was speaking about higher threshold of contact.
“I still believe – and it’s my personal opinion – that if a player is applying contact behind a player that’s got across them, and it spins around – and Leah has not dived, right?
“So there’s contact enough for me for a penalty.”
James’ 85th minute finish buried the chances of a draw with the loss leaving United’s title hopes looking slimmer.
They will hope to bounce back when they host Aston Villa this Sunday following their midweek Conti Cup group stage clash with Manchester City.