Southampton suffered a setback on their return to Premier League action, as they fell to a 3-0 defeat at Brentford that kept them at the bottom of the Premier League table.
After a week of FA Cup and Carabao Cup duties, Saints went to London hoping for a result that would see them climb from 20th in the standings, but quick-fire goals from Ben Mee and Bryan Mbeumo late in the first half and an 80th-minute header from Mathias Jensen put paid to those chances.
Although little consolation, there was at least some positive news as deadline-day signings Kamaldeen Sulemana and Paul Onuachu both made their debuts as half-time substitutes.
Jones had been able to include them on the bench after both players received their international clearance just in time to link up with the squad and be eligible for inclusion.
The Saints boss reverted to a back four from the start, with James Bree starting at right-back in place of the injured Kyle Walker-Peters. Lyanco dropped to the bench, while Charly Alcaraz and Adam Armstrong were also named as subs having started in midweek at Newcastle. Romain Perraud, Roméo Lavia, Mohamed Elyounoussi and Sam Edozie were the four players who came into the starting line-up.
Brentford, who were unbeaten in eight Premier League games coming into this match, made two changes from the team that drew at Leeds last weekend, as Aaron Hickey and Joanne Wissa replaced Kristoffer Ajer and Mads Roerslev.
The home side started well and they had a huge chance to take the lead on eight minutes. Ivan Toney lobbed a ball over the Saints defence, and Yoane Wissa was able to push it round Gavin Bazunu as it dropped, but his resulting shot slammed against the bar with the goal at his mercy.
Shortly after, Brentford carved out another big opportunity, as Mbeumo drove into the left side of the area and squared for Toney around 12 yards out, only for Mohammed Salisu to throw himself in the way of his low, left-footed shot and divert the ball clear.
Saints did then settle and they could have taken the lead themselves in the 14th minute. Ibrahima Diallo’s angled ball from a deep position picked out the run of James Ward-Prowse into the left side of the box, with the skipper controlling it to perfection. Faced with the choice of shooting, or trying to square for Ché Adams, he opted for the latter, but sent the ball just slightly behind his teammate.
It was soon Brentford who were again threatening, and Mbeumo probably should have done better when a loose ball fell to him just inside the area, dragging his resulting left-footed shot wide of the far post.
Still, Saints were not without their own moments, and a nice move between Edozie and Bree down the right ended with Edozie’s shot from inside the box being well blocked by Bees captain Christian Nørgaard.
That was as well-timed an intervention as Salisu’s next block at the other end, with the defender once again being in the right place to deny Toney as he set his sights from about 12 yards following a smart passage of play that had worked the ball into him.
The reprieve was a short-lived one, though, as Brentford did take the lead on 41 minutes.
Mbeumo clipped a cross in from the left and Mee charged in to meet it six yards out, thumping his header into the top corner. In the process, the Brentford centre-back clashed heads with Salisu, with both players requiring immediate attention, although they were fortunately each able to continue.
Almost immediately, things went from bad to worse as the hosts doubled their lead. It was another simple goal, as they won the ball on halfway, set Wissa into the area with an angled ball and he played a square pass from the left side of the area to Mbeumo, who was unmarked in a central position, and he swept home with his left foot.
It left Saints with a mountain to climb in the second half.
Jones used the break to send on Onuachu and Kamaldeen, in place of Elyounoussi and Diallo. Kamaldeen quickly had an impact, sharply cutting in from the left and firing in a low shot from 20 yards that Brentford keeper David Raya held, but it was a good show of intent from the winger.
As a whole, Saints were posing more of a threat, with Perraud forcing a good stop from Raya with a driven, low shot from 18 yards, while Ward-Prowse fired a strike over from just outside the box.
It prompted Brentford boss Thomas Frank into a pair of changes on the hour mark, as Hickey and Josh Dasilva were withdrawn, in favour of Roerslev and Vitaly Janet.
Jones then followed with another double substitution of his own, sending on Alcaraz and Theo Walcott for Lavia and Edozie.
After Salisu had cleared off the line from Toney, Walcott went close to pulling one back on 72 minutes, as the ball dropped to him in the area, but his low shot that was destined for the bottom corner was somehow blocked by a pair of Brentford defenders.
A matter of seconds later and Walcott came close to scoring again, latching onto a long clearance from Bazunu that flicked off the head of Mee, but Raya rushed out of his area and managed to block his effort, with Adams then looping a header just wide from 20 yards with the rebound.
Saints continued to push, and Ward-Prowse rifled a shot just over from 25 yards as the clock hit 75 minutes.
But, for all of those moments, it was to be Brentford who would find the back of the net, as Rico Henry's cross from the left in the 80th minute was attacked by Jensen, who flicked a header into the far corner, removing any remaining doubt there may have been about the result.