World Champion Van Gerwen has taken European Tour glory in Munich and Saarbrücken over the past fortnight – adding to a win in Leverkusen in March – and averaged 106 as he opened his Graz account in style against Lennon.
The Irish youngster had just one dart at a double in the contest, missing tops to win the opening leg, as Van Gerwen raced through the tie with the aid of three 180s, a 177 and six doubles from nine attempts.
"It was far from perfect but for the first game it's not too bad," said Van Gerwen, who now meets Stephen Bunting in Sunday afternoon's third round.
"I love the European Tour events and I'm going to focus myself on my next game and I hope I can do some more damage."
Bunting also enjoyed a whitewash in Saturday's second round as he finished six doubles from 11 attempts in seeing off number 16 seed Darren Webster.
Five other seeded players also exited the event in Saturday's afternoon session, including reigning champion Jonny Clayton as the Welshman lost out 6-2 to Poland's Tytus Kanik.
Clayton led 2-1 early on, but Kanik took advantage of missed doubles from his opponent to move ahead and pulled clear with a second 14-darter before sealing his place in the final day on the European Tour for the first time.
World Championship finalist Michael Smith was defeated 6-4 by Steve Beaton, who averaged 102.41 in a heavy-scoring display as he moved into the third round.
Mark Webster produced an outstanding 11-darter in the deciding leg of his tie with Joe Cullen, while Lithuania's Darius Labanauskas averaged over 100 for a second successive day by defeating Ricky Evans 6-3.
Dave Chisnall was another seeded player to exit the event, going down 6-4 to Nathan Aspinall in a game where both players averaged over 100, with the UK Open champion taking out 143 to seal victory.
Aspinall now meets Adrian Lewis in round three, after the two-time World Champion came from 5-3 down and survived a missed match dart from Ryan Searle to snatch victory with a 14-darter.
German Darts Championship winner Daryl Gurney set up a third round tie with Mark Webster by defeating Russia's Boris Koltsov 6-2, reeling off the final four legs without reply.
Grand Slam of Darts winner Gerwyn Price will now play Labanauskas after enjoying a 6-3 win over birthday boy John Henderson, hitting six doubles from seven attempts in a first-rate display of finishing.
The contest was also remarkable for both players averaging exactly the same at 91.67, with Price coming out on top as he moved into the final day.
2018 World Champion Rob Cross edged out Jeffrey de Zwaan 6-5 in a thriller, with the Dutch youngster finishing 115 and 121 in taking a 3-1 lead only to later miss three match darts in the deciding leg.
Peter Wright was another 6-5 winner, having seen Chris Dobey hit back from 5-2 down to take their game all the way before a 104 finish moved the Scot through to face Kanik in the last 16.
Mensur Suljovic celebrated his 6-4 comeback win over Raymond van Barneveld with an emotional ovation from the Austrian crowd as the home favourite set up a third round tie with James Wade.
Van Barneveld took out a 13-darter and a 121 finish as he took a 3-1 lead and also finished 107 in leg eight to level after Suljovic had moved ahead with three straight legs.
Crucially, Van Barneveld missed his chance to lead once again in leg nine with one miss at double 14, before Suljovic swooped in the next to seal victory with an 11-darter.
Wade, meanwhile, progressed to the third round with a dominant 6-2 defeat of Mervyn King, who paid for ten missed darts at a double during the contest.
Ian White edged out Jamie Hughes 6-5 for a second time this year on the European Tour following another tight battle between the pair.
Hughes led 3-1 before White took three successive legs to move ahead, and the pair continued to trade blows before the deciding leg saw the 2018 Dutch Darts Championship winner finish 61 with his rival waiting on 16.
White now faces Keegan Brown, who was a 6-4 winner over Germany's Max Hopp in the battle of former World Youth Champions as the Isle of Wight ace sealed victory with a 100 finish.