London - Owen Farrell's goalkicking proved the difference as Saracens eventually overwhelmed Wasps 57-33 to book a place in England's Premiership final against either champions Exeter or Newcastle.
Saracens were just ahead on try-count, 6-5, at their Allianz Park ground in north London come the finish of the first of two Saturday's playoff semi-finals.
But England centre Farrell's 27 points in a flawless kicking display helped ensure Saracens remained in command for most of the match, although Wasps fought back superbly after being seemingly out of contention at 30-5 down early in the second half.
Saracens' pack, with Maro Itoje one of several impressive England internationals on show, also played a key role in ensuring the home side would travel across London for the Twickenham final a week on Saturday.
But a match played in glorious sunshine, with England coach Eddie Jones among the crowd, produced some mixed news for the Red Rose ahead of their upcoming three-Test tour of South Africa.
Saracens' Billy Vunipola and Wasps' Nathan Hughes, England's first-choice No 8s, both returned from long-term injury problems.
Vunipola, however, did not appear for the second half after receiving further treatment for the hamstring problem that delayed is return from a broken arm.
Saracens, however, insisted this was a precautionary move. Meanwhile Hughes, who had not been expected to play again this season after knee surgery and was left out of the South Africa squad as a result, could yet force his way back into the party to face the Springboks after playing three-quarters of this gruelling match.
Farrell, who will be England's captain in South Africa in the absence of the injured Dylan Hartley, sent Saracens on their way as early as the second minute when he went between Ben Harris and Joe Launchbury before releasing Alex Lozowski for the opening try.
Vincent Kock took Saracens further ahead with their second try before South Africa's Willie le Roux started and finished a try-scoring move to give Wasps a foothold in the match.
However, it looked as if Saracens were all but out of sight when veteran United States wing Chris Wyles dive over in the corner for a try early in the second half.
Wasps though were far from finished, with Jake Cooper-Woolley crossing for a try that sparked a bewildering quick array of scores.
Danny Cipriani then released speedy wing Christian Wade, who found Thomas Young for yet another Wasps try.
In the midst of the Wasps' revival, Farrell's fourth and fifth penalties gave Saracens a measure of breathing space only for their opponents, thanks to more good work by Cipriani and Guy Thompson, to send le Roux in for their fourth try.
Saracens managed to keep their composure and some solid drives close to the Wasps' line paved the way for a try by Juan Figallo.
Itoje and Wade then exchanged tries before Saracens replacement scrumhalf ended the try-scoring in a semi-final that entertained the crowd but doubtless gave the defence coaches on both sides a torrid time.
