Middlesbrough's automatic promotion hopes were severely dented as Conor Chaplin's 97th-minute winner helped lowly Portsmouth to a shock 1-0 win at the Riverside Stadium. 

The result sees Middlesbrough remain fourth in the Championship after Ipswich Town's earlier win over rivals Norwich City, with the Tractor Boys also boasting two games in hand. 

Chaplin's late goal also improved things at the opposite end of the table for Portsmouth, who hauled themselves out of the bottom three and above Oxford United. 

The hosts came close to opening the scoring early on through Alan Browne, but his low drive was repelled by Nicolas Schmid after good work from winger Jeremy Sarmiento. 

Schmid again came to Portsmouth's rescue early in the second half to deny Riley McGree's fierce attempt, before Tommy Conway saw his shot narrowly evade the far post. 

But for all of Middlesbrough's pressure, they were undone in second-half stoppage time by Chaplin, who deflected Adrian Segecic's volley from the edge of the box into the net. 

Elsewhere, Southampton came from a goal behind to move up to fifth in the standings, after beating fellow play-off rivals Derby County 2-1 at St. Mary's. 

Fresh from their thrashing of Wrexham, the FA Cup semi-finalists fell behind seven minutes before the break when Carlton Morris prodded home at the back post from a corner. 

But Southampton drew level in the 62nd minute when the lively Leo Scienza rounded off a free-flowing counter-attack with a brilliant curling finish past Richard O'Donnell. 

And Taylor Harwood-Bellis completed the turnaround seven minutes later, as he headed in Ryan Manning's inviting free-kick delivery to seal the win. 

But at the opposite end of the table, Leicester City's relegation fears worsened after the Championship's top scorer Zan Vipotnik clinched a 1-0 win for Swansea City. 

Defeat means Leicester drop to 23rd, above only already-relegated Sheffield Wednesday, and they are four points from safety with just four league games remaining.

Data Debrief: Boro's late-season stumble continues

Kim Hellberg would have known the importance of keeping the pressure on Ipswich after their earlier win over Norwich, but his team were unable to respond here, with their poor run at such a crucial stage of the campaign continuing. 

Middlesbrough are now winless in their last six Championship games (D3 L3), their longest run of the season, and it was once again their profligacy in the final third that proved costly in their quest for a return to the Premier League. 

Boro finished with an expected goals (xG) total of 1.28 from their 20 shots, eight of which were on target. Meanwhile, Portsmouth registered a 0.51 xG from their three attempts, with Chaplin's match-winning moment their only shot on target.