Gerrard scored in the second minute and made it 2-0 after 38 minutes with Ryan Babel adding the third seven minutes from time.
Liverpool, who have now won nine of their last 10 league matches and drawn the other, moved on to 80 points and above United on goal difference.
However, Liverpool only have two league matches remaining while champions Manchester United have four, beginning with their derby against Manchester City at Old Trafford on Sunday.
Third-placed Chelsea face fourth-placed Arsenal on Sunday at the Emirates Stadium and a win for United and defeat for Chelsea will mean Liverpool will be the only team still in with a mathematical chance at least, of stopping United winning a third successive title and equalling Liverpool's all-time record of 18 championships.
Gerrard struck the opener when he beat the Hammers offside trap and rounded goalkeeper Robert Green to score. He took his goal tally to 23 -- his personal best for one season -- after 38 minutes when he followed up to force the ball home after Green saved his penalty. It was Liverpool's 100th goal in all competitions this season.
The 101st came late on when Babel tapped in the rebound after Green had saved the Dutchman's header.
With none of the other top four teams playing much of the focus centered on the bottom of the table, and West Bromwich Albion, who pulled off a famous escape from relegation in 2005, could be on their way to surviving in the Premier League again after beating Wigan Athletic 3-1 at The Hawthorns.
Marc-Antoine Fortune scored twice as West Brom won for the second time in three matches to keep alive their hopes of avoiding an immediate return to the Championship.
"We will just keep going," said West Brom manager Tony Mowbray, whose team could have been relegated on Saturday had results gone against them.
"It all rests on next week's game against Liverpool. If we can get some sort of result and take it to the last day against Blackburn then anything can happen."
West Brom stayed bottom but moved on to 31 points, the same as Newcastle United and Middlesbrough who meet on Monday.
Hull suffered a fifth straight loss, going down 2-1 to Stoke City, who are now safe. Hull have 34 points, two behind Sunderland who are also deep in trouble on 36 points after drawing 0-0 at Bolton Wanderers.
FORTUNE STRIKES
Fortune gave West Brom the lead after eight minutes before Hugo Rodallega equalised for Wigan with a 25-metre free kick which took a deflection off Chris Brunt.
Brunt made amends when he put West Brom back in front on the rebound after his penalty was saved by Wigan's substitute keeper Richard Kingson, who had replaced the injured Chris Kirkland.
Fortune sealed the win with his second after 73 minutes.
