In a match played to a high standard, Gilbert knocked in three centuries including a match-sealing run of 115 which capped an impressive display.
Stevens, twice a runner-up at the Crucible, was on the back foot early having slipped 4-1 behind, but he played really well in the evening session and at one stage reduced his arrears to 8-7, before Gilbert finished the job in ruthless fashion.
Another to impress on Thursday was Jimmy Robertson who brushed aside Anthony Hamilton 10-2, while David Grace will make only his second appearance at the Crucible having comfortably seen off Andrew Higginson 10-5.
Vafaei books Crucible return; Davis knocked off tour
Hossein Vafaei will make his second visit to the Crucible in as many years following his 10-6 victory over Jackson Page.
Vafaei was the more assured of the two players in the first session, ending it with a 6-3 lead, and he was able to keep his younger rival at arms length in the evening.
In the battle of the veterans, Joe Perry fought back from 9-8 down to edge past Mark Davis 10-9.
Despite making a break of 55 in the deciding frame, Davis had to watch on as Perry won the frame and match on the final black, a result which confirmed Davis will drop off the tour after 32 years as a professional.
Other notable winners on Wednesday were Elliot Slessor and Pang Junxu, the former beating Zhou Yuelong 10-5 to record one of his biggest victories of the season.
