Amadou Bakayoko scored a first-half hat-trick as five-star Walsall thumped League Two Grimsby in Northern Group H of the Checkatrade Trophy.
Andrew Boyce gave the Mariners an early lead, but a 26-minute Bakayoko treble put Jon Whitney’s side in control at the break.
Kieron Morris netted his third goal in as many matches to make it 4-1, before Luke Summerfield pulled one back.
But the Saddlers had the final say, with youngster Maz Kouhyar’s first career goal - on his full debut - putting the gloss on a comprehensive win.
Grimsby made the brighter start and took the lead after six minutes, when a Summerfield free-kick was headed back across goal and turned in by Boyce from close range.
Paul Hurst’s Mariners, back in the EFL this season after a six-year absence, looked full of confidence in the opening exchanges.
Omar Bogle – Grimsby’s hat-trick hero against Stevenage on Saturday – fired wide from distance, while Zak Mills and Summerfield each tested Craig MacGillivray, as Grimsby pushed for a second.
The Saddlers had started sluggishly but they soon improved, equalising on 18 minutes.
Erhun Oztumer slid the ball through for Bakayoko, whose left-footed shot took a wicked deflection off Shaun Pearson and looped over stranded Town keeper James McKeown.
Walsall – searching for their first win since the opening day - began to take control, with Morris twice trying his luck from distance.
He first fired off target after a decent passing move, before then stinging the palms of McKeown with a well-struck 25-yard drive.
Jon Whitney’s side went ahead six minutes before the break, as Liam Kinsella played in Bakayoko who coolly slotted past McKeown into the far corner.
Just five minutes later the young frontman was celebrating his first career treble.
He controlled Joe Edwards’ cross on the edge of the box, turned Josh Gowling and bent a super left-footed strike beyond the keeper.
Half-time: Walsall 3-1 Grimsby
The Saddlers came inches away from extending their advantage shortly after the resumption, when Oztumer's left-footed free-kick curled a whisker wide.
Grimsby almost pulled one back on 52 minutes, but MacGillivray made an excellent diving stop to keep out Disley’s shot on the turn from point-blank range.
Oztumer then went close with an audacious effort from around 45 yards which drifted narrowly over, before Walsall made it 4-1.
The diminutive playmaker was inevitably involved, threading a pass through for Edwards, who cut the ball back for Morris to apply the simplest of finishes.
Grimsby refused to lie down and reduced the deficit midway through the second period, Bolarinwa reaching the byline and crossing low for the onrushing Summerfield to tap home.
But Walsall’s three-goal cushion was restored just four minutes later.
Kouhyar controlled Edwards’ long diagonal pass, took the ball beyond the last defender and finished confidently past McKeown at his near post.
The visitors should have made it 5-3 late on, as Mills put the ball across for Vose who could only head over from close range.
Full-time: Walsall 5-2 Grimsby
Team: MacGillivray, Edwards, McCarthy, Dobson, Oztumer, Morris, Kinsella, Preston, Bakayoko, Kouhyar (Ginnelly 72'), Cockerill-Mollett.
Subs not used: Hallwood, Sangha, Roberts, Shorrock, Peters, Tonks.
Attendance: 1,022 (66 Grimsby supporters).