Pompey fought back from two goals down to get a gutsy point at Adams Park this afternoon.
Wycombe Wanderers netted twice in three minutes to reflect a poor first-half from Paul Cook’s below-par side.
However, Lavery pulled one back two minutes into first-half stoppage time to provide hope.
And Webster secured a point to the delight of the 1,976 visiting fans when he headed home Ben Davies’ corner.
The Blues finished strongly and Christian Burgess had appeals for a penalty waved away, but it finished 2-2.
Pompey had fallen behind in the 27th minute when Brian Murphy’s poor clearance eventually fell to Michael Harriman, who shot from 30 yards into an empty net.
Matters worsened three minutes later when Harriman’s magnificent cross from the right was turned home by Garry Thompson inside the six-yard box.
Pompey perked up following the second goal and reduced the deficit into three minutes of time added on when Marc McNulty unselfishly squared for Caolan Lavery to finish.
At half-time Adam Barton was introduced for Danny Hollands in midfield and 10 minutes after the break Webster levelled with a header from Davies’ right-wing corner.
There was to be no more drama, however, has Cook’s men collected a fine point at the Chairboys.