Jermaine Easter's goal gave Wycombe a shock draw against Chelsea in the first leg of their Carling Cup semi-final.
Easter's strike overshadowed substitute Lampard's efforts
The League Two side made a strong start and Kevin Betsy forced Hilario into a good save with a shot at the far post.
But Chelsea soaked up the pressure and Wayne Bridge gave them the lead when he beat Wycombe keeper Ricardo Batista to Salomon Kalou's pass and lobbed home.
Wycombe looked like they had run out of ideas until Easter met Tommy Mooney's flick and rolled the ball home.
It means there is still everything to play for when the two sides meet for the second leg at Stamford Bridge on 23 January.
606 DEBATE: Your views on the match
Chelsea's form over Christmas was unconvincing to say the least but few can have expected them to fail to see off Wanderers.
Jose Mourinho's defence did have an unfamiliar look about it, with Michael Essien partnering Paulo Ferreira in the centre because of the Blues' problems in that position.
Chelsea were also missing the suspended Didier Drogba up front and, with Andrei Shevchenko injured, it was left to Kalou to play as a lone striker with Shaun Wright-Phillips and Wayne Bridge deployed on either flank.
Kalou saw little of the ball early on as Wycombe made a strong start - while at the other end Essien had to contend with the bustling style of Easter and Mooney.
Wanderers had already beaten two Premiership sides - Fulham and Charlton - on their way to the semi-finals and they were showing the conviction that they could make it three.
They created the game's first real chance, which came on 19 minutes when Stefan Oakes released Easter on the left.
The Welshman's cross reached Betsy and Hilario had to react quickly to push his fierce shot over the bar.
But you always knew there was more to come from Chelsea and they slowly began to impose themselves on the game.
Just after the half-hour mark Bridge went close from a corner when his volley was cleared off the line by Tommy Doherty, but he did not have to wait long to find the net.
Kalou's precise pass released the England international and he lifted the ball over the onrushing Batista and into the net before colliding with the keeper, meaning he had to celebrate his first goal in three years with the physio.
That could have been the platform for a sustained period of Chelsea pressure but instead they sat back and appeared content with their lead.
Wycombe were invited to come forward but seemed unable to break down the Blues defence, apart from when Matt Bloomfield ran clear only to slice his shot horribly wide.
Even when Frank Lampard came off the bench Chelsea's attacking ambition seemed limited, and they were punished in the 77th minute when Easter snatched an unlikely leveller - his 19th goal of the season.
Mooney flick released the big striker and he held off Essien before getting enough on his shot to beat Hilario and send the Adams Park crowd wild.
It almost got even better for Wanderers when Oakes sent a late free-kick curling just over but Paul Lambert's side can still be proud of their display in holding the Premiership champions.
Wycombe: Batista, Martin, Antwi, Williamson, O'Halloran, Oakes, Bloomfield (Torres 75), Doherty, Betsy, Easter, Mooney (Dixon 88).
Subs Not Used: Young, Palmer, Anya.
Booked: Mooney, Williamson.
Goals: Easter 77.
Chelsea: Hilario, Geremi, Bridge (Lampard 67), Ferreira, Ashley Cole, Essien, Makelele, Mikel, Ballack, Kalou (Sinclair 90), Wright-Phillips (Sahar 61).
Subs Not Used: Kalambay, Morais.
Booked: Makelele, Mikel.
Goals: Bridge 36.
Ref: S Bennett (Kent).