Saints led inside the opening two minutes at St. Mary’s, but they were undone by a controversial sending off of Nathan Redmond which visiting Tottenham capitalized on for a 4-1 win.
Southampton went ahead just 70 seconds into the match when a free-kick from James Ward-Prowse curled into a perfect position, and Virgil van Djik lept incredibly high to meet it, powering home the header for a lightning-quick 1-0 lead.
Following the goal, Southampton pressed incredibly hard, throwing Spurs completely out of whack. With Tottenham back on their heels, Saints ran them ragged for the opening 15 minutes, with the best chance for a second coming on 17 minutes when a dangerous cross from Ryan Bertrand down the left nearly met Jay Rodriguez who had beaten Danny Rose, but Rose recovered to make the tackle at the last second. The ball sat untouched for a moment, eventually cleared.
Finally, Tottenham recovered, and took advantage of a lucky break. After finally collecting themselves, a 19th-minute cross from Moussa Sissokho clipped the back of Nathan Redmond and popped high in the air. Dele Alli found himself all along in front of net, and he met the ball with his head, directing it on and in despite a last-ditch challenge from van Djik.
Following the Spurs goal, the game slowed and things became cagey. The next good chance didn’t fall until the 43rd minute as Victor Wanyama received a ball from Rose in the box and glided past a defender, but the Kenyan couldn’t get a shot off in time, and he was closed down by Jose Fonte who slid in and deflected the shot out of danger.
The halftime break came and went, and Spurs would take the lead shortly after. In the 53rd minute, Harry Kane rose above Oriol Romeu to meet a corner, and he bagged the game’s third headed goal to put Spurs up 2-1.
It would get far worse for Saints, as Sissokho fed a delicious ball to Alli on the break just moments later. Alli was challenged hard by Redmond, and appeared to stumble near the top of the box under a slight shirt pull. The young Spurs midfielder recovered and eventually fired wide, which caused referee Mike Dean to pull back advantage and award a penalty, also handing Redmond a red card for denying a clear goalscoring opportunity. The decision was controversial because it looked clear that Mike Dean awarded the decision for the pull, which clearly happened outside the box with defenders in the area.
With Spurs a man up and a chance to put the game away, Harry Kane blasted the penalty miles over the bar, looking back down at the turf where a sizeable divot was evident next to the ball. Replays show his plant foot slid a good distance on the kick, causing the ball to sail so high.
The man advantage allowed the visitors to dictate the pace of play, and they had another big chance on the 70-minute mark as a cross from Sissokho right along the baseline clipped out to Christian Eriksen at the top of the box, and with all day to pick a shot, he rattled the crossbar.
Spurs finally put the game away with a breakaway goal from substitute Heung-Min Son in the 85th minute, and Southampton were unable to put forth any significant fight down a man. They added salt to the wound with another two minutes later as Danny Rose displayed some silky moves and Alli finished it off cooly.
The win moves Spurs to 36 points, back within just one of Arsenal in the final Champions League place. Southampton, meanwhile, stays in the top half of the table, but fails to capitalize on the opportunity to move further towards a more guaranteed Europa League position.