Schalk Burger scored on his Aviva Premiership Rugby debut as reigning champions Saracens blew Worcester Warriors away with a second-half blitz to secure a bonus-point win at the London Double Header.
Carl Hogg's side defended admirably in the first-half and new Saracens fly-half Alex Lozowski missed two kicks on goal as the two sides went in at the break finely-poised at 6-3.
But Mark McCall clearly had strong words at half-time as Saracens looked every inch the defending champions when they emerged for the second-half, Lozowski knocking over a penalty almost immediately before Jamie George scored from a driving maul.
Burger traded passes with countryman Schalk Brits then capitalised on superb play from Billy and Mako Vunipola before powering over, and Ben Spencer then lit up Twickenham with a super individual score in the dying moments.
New Zealander Jackson Willison was penalised for going off his feet at the breakdown, and new man Lozowski knocked over the three points after 20 minutes.
Ben Te'o put in a perfectly timed shot on England hooker Jamie George and he continued to make his presence felt when he looked clean through for the opening try, but Alex Goode covered well.
George was prominent in attack and an inside ball from Richard Wigglesworth sent him haring through to the line but he was hit hard by Dean Hammond before Niall Annett gifted Lozowski a shot that he scraped wide.
Ryan Lamb then pulled Worcester level from the tee on 27 minutes after England lock George Kruis was pinged for infringing at the line-out.
Saracens made the most of a directionless Worcester kick, stringing the phases together to take them deep into the opposition 22.
It then took a strong Hammond cover tackle on Chris Ashton to rescue the Warriors and as the ball was recycled Kruis reached for the line, but came just short.
Lozowski made amends for two errant penalty attempts with a well struck three-pointer just before the break.
The former Wasps man then doubled Sarries' lead immediately after half-time when Tevita Cavubati gave away a clumsy penalty in a kickable position.
Warriors attempted to attack from deep inside their own half and when Sean Maitland intercepted a loose pass, Worcester gifted Saracens priceless field position with a breakdown penalty.
George then got the try he deserved five minutes into the second-half. On his 150th appearance for Saracens, he was the at the back of a tightly-packed maul which the Champions marched over Worcester's line for their first try of the season, which Lozowski converted.
A wave of Worcester replacements barely had a chance to find their feet when a faked driving lineout put Vunipola into space.
The England No.8 was brought down just before the line, but the ball was recycled and South African World Cup winner Burger sent Lozowski over for his first Saracens league try, which he then converted to put his side 23-3 up after 53 minutes.
With Worcester down to 14 men, Burger was instrumental in creating his own try five minutes later, exchanging passes with Schalk Brits at the line-out and then again in open play before bulldozing over under the posts, before Lozowski easily converted.
Spencer created something from nothing with two minutes remaining, breaking from outside the 22, stepping superbly and dancing home for an outstanding individual score.